Whatever length your rig is, there will be sites you can't use.
Our TT is 21 feet, hardly "big" by anybody's standards, and on a couple occasions, we've been excluded because they didn't have any sites big enough. Rather, it was because all their sites that would work for us are already taken.
Most of the time, that's no problem, but if you really want to NEVER be unable to "stay there," . . . well, it can't be done. There are even campgrounds that do not allow tents, as well as ones that are tents-only.
34 feet is a big rig in almost everybody's book. But if that's what you need, then that's what you need. Yes, there will be times when you won't fit in anything that is available, and you'll have to camp somewhere else. But I wouldn't expect it to be a big issue.