4 seasons insulation

We are shopping for a 5th wheel to fulltime in all over the US. Concerning 4 seasons insulation, how cold can you use these without a skirt, and with a skirt - before lines start freezing? What other problems with the RV are we likely to encounter winter camping? Are all the manufacturers "4 season" insulation packages pretty much the same, and what should we make sure it includes (heat blankets on tanks, heat tape on all lines, etc.? Thanks!
4 seasons insulation


To start with No not All Manufacturers are the same. Some will say four-season and some will say full time. 4-Season and Full time are two different things. Make sure warranty is not void if you use one full time, You must have heavier insulation in your unit if you are going full time in the colder area's. Reason R-7 units with the four season pkg. will sweat your windows up and in the walls also. This is a major problem. I know our Carriage Mfg. warranty is not void with full timers. Matter of fact they encourage it. The insulation is a stronger pkg. Also make sure that the dump valves are enclosed also. With the Carriage two floor system you will have the tanks in between and heated during the colder days. Check out the different units, Several Mfg. are now going after the full timers not just Carriage.