The 31' Cs with slides often have serious payload issues. I could not find listed empty weights for the Jayco 31FS, but I seem to remember they sit around 13,000 empty.
I used to have a 30' C Gulfstream bunkhouse model with two dinettes and no slides. It's listed empty weight was 11,500, but fully loaded for camping it was difficult to not overload the rear axle. And it had a wheelbase of over 200 inches, so for a coach of its size there was not a great deal of overhang. My point is that you will very likely run overloaded in this rig.