I think that will depend heavily on what kind of meat you start with and how long you cook it. Several times we've cooked chuck roast in the sous vide (~24 hours) and it comes out so tender that you could tell your guests that it was prime rib and might well be able to fool quite a few of them. I think a lot of people use the shortest possible safe cooking time for their sous vide meals without considering that cooking a bit longer will make the final result more tender.
For example, tonight I'm going to cook a ~1 pound pork tenderloin. It would probably be safe to eat after ~2 hours, but I will cook it at least 3 to get the tenderness we like.
We used public parks all the time with our 40' motorhome and had no problems..... out west. However, we have done state parks and Corp of Engineer parks in the midwest and south east with no problem either. I can tell you that a 26' trailer in the West would have no issues, whatsoever.
Since you're in the east I suggest you look at the web sites of some favorite parks that you would go and see what size their sites are.
If you got the 22' I think you might be sorry since you like the 26' now.
In reading the "comments" below this 'long recipe' some folks noted that the beef was tough. I'll be interested in your take after making this and what kind of beef you used.