Pour some warm water in. If you don't have a shower bring a cooler full. Also, can wear a ski parka, hat, gloves and boot liners in the boat. Don't take the wetsuit off unless you have a way to warm it. It's much worse to put a cold suit back on. Lots of the guys I go with wear dry suits and neoprene booties even inside their bindings. Of course we're in Wisconsin and don't get to that point until temps are 40's. We've made outings as low as 33-32 for a combined temp of 65. That involved a little ice, but was quite fun.
I spent most of my money on booze, broads and boats. The rest I wasted. - Elmore Leonard