We started with a 22'3", tongue to bumper, TT with spring under and 205/75R14 tires. It had more ground clearance than any of our friends similar sized trailers, and we put it into some small places.
After a few seasons we upgraded to our current TT, which is 29'3" tongue to bumper. It came from the factory with a spring over suspension, and 225/75R15 tires. I had to raise the ball 4.5" over my last camper, so it sits quite a but higher.
So far I cannot think of any places the bigger TT has limited us in campsites, and nearly all of our camping is boondocking. It's rare for us to stay in a campground, and each trip usually involves 5-50 miles of dirt, one way. The added ground clearance of our current TT is what has made it able to fit in many places a standard height TT wouldn't fit. Our total length is 51'7".