I've ridden out some 50+ mph winds in my Aliner (on the top of the mountain in Queen Wilhelmina SP in Arkansas.) They buffeted and shook the camper pretty good. Much more than this and I would seek shelter - and that's with secure, hard sides. But again I probably wouldn't want to be in a TT in winds much over this as I'd be afraid it might turn over (unless it was facing into the wind). At least there's less chance of this in my Aliner, as there's less wall area up high for the wind to push on.
Chip