shorter vs longer on a long trip

The length isn’t going to make much difference in mileage, as said air resistance is the culprit. The weight comes into play when starting from a dead stop and especially if you’re climbing mountains, then you will notice the difference. I like small because they’re much more maneuverable and the ease of driving scenic roads and finding camp sites. And I don’t like reservations or planning which gas station, parking lot, etc. I can get into. So if I had the option of reselling the shorter TT for the same money I’d choose it. But then I pull a 16’ TT so I'm bias.