NH trailers are heavy but built to last. We've owned two of them, a 38' Summit, and we now travel around in a 41' Majestic (4-5 months/year). Loaded for travel, our Majestic weighs 24,000 lbs (26,250 GVWR). We purchased an International MDT in 2006 from 2L Custom Trucks in Poolville, TX when we purchased the Summit and still use it to tow the Majestic. It does a great job (315 hp/1000 lb-ft/air brakes), and I'm glad we invested in it years ago. We have 125,000 miles on it, and it's just now getting broken in. It'll easily last another decade or more.
Plenty of NH owners, however, seem to do fine using F-450's and F-550's or their Dodge Ram counterparts (a lot depends upon the length/weight). Several others use MDT's like ours while some have gone to the dark side with Class 7 tractors. Trailers this long take some advance planning when camping, but we've utilized Colorado State Parks numerous times with great success. Most commercial parks, at least out west, seem to have little difficulty handling big rigs like these.
Hope this helps. Good luck.
2007 Int'l 4400 from 2L Custom Trucks
2013 New Horizons Majestic, F41RL4SS