You will probably be fine with the reduced clearance. Looking at trailer suspensions it doesn't seem like they have nearly the amount of travel that car/truck suspensions do.
I did the upgrade but used 245/75R16s because I had a great deal on a set. I ended up raising my trailer (next holes on spring hangers) but I think I didn't need to. I'm contemplating dropping it back down because of issues with the entrance steps being too high.
I've been on the 16" wheels and tires for years and have not had any issues. When I was on 15" tires, it was about 1 tire blown a year. This was on about 4 different campers ... it's nice to leave the STs behind and have a quality LT tire.
