I've got a '07 Sierra 33' 5th wheel that I use while working out of town, this is the 3rd winter I've spent in it, it's not a 4 season trailer. This summer I plan on doing some modifications on it to make it more comfortable. Any help or advice on products, links, or procedures would be greatly appreciated. I'm thinking about spray on foam insulation, something for the water lines, the city water connection, and possibly something to do with the furnace ducting. Also are there schematics for the plumbing, electrical, and mechanical systems on these trailers or is it a search and destroy mission?