This was the argument my wife and I had for 6 months before buying our TT. She wanted to go to NP and SP (we live in California). We bought a 2702WS TT which is 32ft tip to tail and book sites that are 30ft. We fit into a 30ft NP or SP site because they do allow some over hang. My buddy has a hard time going with us because his is 36ft and 35ft spots are a much less available size and not available at all in some parks.
2016 Rockwood 2702WS
2016 Chevy 2500HD Duramax 4x4 High Country