2WD, SRW pick ups have got to be the worst vehicles on the road for traction in slippery conditions i.e.: snow/ice, wet clay/grass, mud , loose sand etc. (except for maybe DRW). Most of the weight is up front especially with a diesel engine. But if you can safely say that you will never be in any of these situations, then maybe you can get by with a 2WD truck.
Personally I see these conditions especially snow every day for 4 or 5 months every year as I have a steep and long driveway and we also drive up in the mountains almost every day to access skiing. It is a well maintained driveway but even though I have a new truck and brand new studded snow tires, I can make it up the driveway maybe 100' in 2WD before spinning out. Of course I have a 4X4 so traction is no problem. It was my choice to have a good view and privacy that required a long steep driveway and therefore a 4X4 truck.
Back to the OP. Your RV lifestyle will dictate whether to get a 2WD or 4WD truck to pull your TT. But remember that you may be using this truck for a lot more duties than pulling a TT. Hunting, fishing, beach travel, skiing, sledding, quading, hiking , sightseeing ,firewood gathering, winter travel to work may mean you will need more traction than what a 2WD truck will give at some time.
Around here, almost all new trucks on the lots are 4X4. It is not an option.
Dave