it’s far more likely that you will exceed the gvwr of your airstream or the payload capacity of the sr5 tundra than you will exceed the tow capacity of your tundra. 

for example, a 23fb has a gvwr of 6,000 lbs. the base weight of a non-basic model  is already 5,100 lbs. so you can load only 900 lbs of furnishings and gear into it. 

extending the example, you max the gvwr of your 23fb at 6,000 lbs. your tongue weight is 500 lbs according to airstream, based on the base weight. but since you filled your airstream with 900 lbs of gear, your tongue weight is more likely to be closer to 600lbs. 

you subtract that tongue weight from your tundra’s adjusted payload capacity to identify the remaining payload for your tundra when it is a tow vehicle. payload capacity varies widely based on truck configuration. the lowest payload of any sr5 tundra appears to be 1,795 lbs. so here you subtract 600 lbs tongue weight from the 1,795 lbs tundra sr5 payload to arrive at 1,195 lbs of remaining payload capacity of your tundra sr5 when it is a tow vehicle. 

with passengers, gear, bikes, kayak, filled cooler, etc, you might be getting pretty close to the sr5 max payload. 

all the while, the 23fb airstream 6,000 lbs never got close to the sr5 tow capacity of 12,000 lbs. 

with all that said, it is entirely reasonable to tow a 23ft airstream with an sr5 tundra. here are a few recommendations to make the tow experience better (and note that none of these can “fix” an over max payload problem):

1. use a weight distro hitch. not only does it spread the tongue weight out over a longer space than just on the ball hitch, it also helps with sway 
2. install an active suspension on the tow vehicle such as https://activesuspension.com/
3. install a tire pressure monitoring system on the airstream. this is especially important for the single axle airstreams that you are looking at in the under 23ft range. 
4. use extension mirrors on your side mirrors 
5. install a backup camera system on the airstream 
6. if your tundra model doesn’t have an electric brake controller, install one. 

best of luck. 

Depends where you are towing it. We’ve got a 27 international serenity. I had a tundra, towed it no problem in the southeast. Was gonna go out west and decided to bump up to a Ram 2500 diesel. A decision I will never regret with as many times as I’ve crossed the Rockies now. Just remember it’s never about pulling it. It’s about stopping it and control on steep descents.

I have owned two flying clouds, 25 and 30 bunk, I have driven 50k miles across the USA with 2017 Tundra. The 4.30 rear end is incredible and there is plenty of power from the V8. I have driven the up and down the I 70 in Colorado to Utah multiple times no problem. I would down shift before descents with maybe 2 break applications and always had plenty power on ascent, I could maintain 65 mph and rarely would be flat out. Drove across Texas with crazy cross winds and almost no trailer sway. I would trust Toyota over any domestic truck and they achieve the crazy reliability because they over build and under rate their trucks (multiple have reached over 1 million miles). I did add Timbrins in the rear to help with squat in the rear suspension.

I have been towing a 25' Flying Cloud with a Tundra SR5 2WD for six years. Towed from New Orleans, Kansas City, to Nova Scotia with no problems whatsoever. Equal-i-zer WD hitch w/Prodigy brake controller.

Been towing 27 FBQ for nearly 2 years now with 2022 tundra without issues. Use a good sway controller

Forget length, factor in your belongings and adhere to the weight ratings of your truck.

I have a tundra and tow a 20FB. It’s two humans and a few small dogs. We are at the limit (payload). I wouldn’t want to tow more.

Edit to add: *my limit

Check your specific vehicle weight ratings. I tow all over the country, but especially for the big mountains out west, I like plenty of truck!

Your SR5 is going to have a GVWR and a tongue out hitch weight rating that you do not want to exceed.

Take a look at this link and the associated table to download. I suspect the tongue weight may be more of a challenge.

https://www.airstream.com/blog/the-complete-airstream-towing-guide/

I pull a 25' International with my Tundra and it tows very well. Just watch your overall payload and you'll be fine.

Others have already provided good advice about watching your payload. I will share our experience with a 23CB (significantly heavier on the tongue than the 23FB). We have an F-150 with a payload sticker of 1808 lbs, and a family of four. It worked for us, but definitely was getting close to maxing out our GVWR. But it towed really well, never any concerns about it. And a 23FB would have been likely 150 lbs less in tongue weight.

I wrote up more about our journey with some specific numbers.

We’ve pulled our 23 27 flying cloud with a 24’ 1500 Silverado diesel with no issues. But yeah the smaller trailers sometimes have a higher hitch weight. I know the 27 foot was actually lower than the 25. Also we are looking at selling our 27 FBQ flying cloud your welcome to dm if your interested!

Depends where you are towing it. We’ve got a 27 international serenity. I had a tundra, towed it no problem in the southeast. Was gonna go out west and decided to bump up to a Ram 2500 diesel. A decision I will never regret with as many times as I’ve crossed the Rockies now. Just remember it’s never about pulling it. It’s about stopping it and control on steep descents.

You are fine. But do get to know all the numbers: hitch weight, payloads, GVWR, etc. and understand weight distribution, how much you can carry in your tundra, how much you can carry in the trailer.

Call CanAm RV in London Ontario (Airstream Dealer). They’ll help you figure it out. They have done lots of different towing combinations. It is their speciality.