I have a Sportsman 18-20' that the Xterra did okay with...~4800#'s loaded/wet. I never had overheating problems it was just a little boggy on steep hills--on the freeway it would run 75+ if that is what you wanted to do. I was also towing it lifted with 33" tires (and all the other armor) and that generally doesn't give you good results. Compared to the F150 I used to pull this trailer with, the Xterra did far better performance wise.

You would want a brake controller (an absolute must for safety!), load distributing hitch and possibly a generator/inverter for using things like the a/c or microwave or recharging.

I personally would not tow a single axle travel trailer...they are just too freaky. I'd rather get a larger one with twin axles, they are a lot more stable, regardless of the wheelbase of the tow vehicle. This size would be the limit of what I would want to tow, but it's very do-able. There are a lot of used units that fit within this size at far better prices than a new one, with better equipment and amenities. That way you wouldn't be too concerned about those dirt and gravel roads getting to the good spots. I would suggest hitting a used RV place and seeing if you could pull a couple of used ones around for a bit to get the feel of them. That would give you the best idea of what was within your comfort range. Good luck.