Can you do it? Probably. Can you do it safely? Well, more likely than not, but no guarantees. Should you do it? Probably not.
I'm a person who has pushed the envelope. I towed a 13' "egg" trailer 2000 miles with a Dodge Omni, back in the '80s when you could rent them from UHaul. Would I do it again? Not likely. I also towed a 23' Rockwood for 3 summers with a 2000 Mercury Mountaineer. Without an Equal-i-zer hitch, handling was downright scary. That TT was only about 4000 lbs loaded, but quite a strain on the old 220 HP V8. Worse still, the tongue was so heavy with a load of water, LP, Equal-izer hitch, and whatnot that I bent a rear spring on the truck. That tell you anything? 285 lb dry hitch weight rating turned into more than 600 lbs loaded, real fast.
Ok, if you want to know what your truck's rated for and whether it has factory tow package, trot down to the Toyota dealer and have them look up your VIN. They should be able to pull up exactly how your truck was configured from the factory, with every option on it. Then you can know your tow rating and your hitch weight rating.
The big problem I see is your hitch weight. You will probably exceed the hitch rating. And when you do that, you risk blowing out the rear tires or tearing the receiver off the truck. Does that sound like a safety concern? You bet.
With a 25' TT you would want some sway control of some kind. Add that weight to the total you're placing on the hitch.
I am assuming your truck has the V8. If it's the V6, it will really have its tongue hanging out. Even the V8 will be taxed with that much trailer behind it, but like you say for 90 miles at a moderate speed (say, 55 mph) it could tow it.
