There is another 165 owner on this forum who posted that he went to 14" wheels and tires without raising the trailer and had no problems. With the Dexter lift kit on mine, there is plenty of room for 14" tires. Based on the clearance I now have, I am pretty sure that I could even go to 15" if I choose, but the plan is to go to 215/75 R14's for both easier availability and a bit more safety range on the weight rating. I will still be limited by the axle rating but believe the 14" tires should run cooler.
2012 Jayco 165
2011 Nissan Frontier