Added the second layer of floor insulation, and foamed the gaps.
Then cut the excess foam.
Cut the clearances in the floor ply for the propane line access, marked where the joists are, so that I can screw things up.
Lay down the Reflectix.
Lay down and screw the floor. It's not what it sounds like.
Rinse and repeat.
There's about a 1' section at the rear and end trim to do. Also, I'm going to foam some gaps, and add Reflectix to the wheel wells. That work will wait for a cooler day. I begin to fear that day will never come.