I have a 14 21FBRS that I worked out of and used for my time off. I'm an IBEW electrician and work on Nuclear projects, oil refineries, paper mills and large industrial projects. I have been in 15 degree to 100 degree locations without serious problems. I had my doubts at the start due to the floor design, no bottom cover. The techs at FR told me the trailer was designed that way, built over Aluminum and pressed insulated panels. It works. If I searched for one "dislike" it would be the tiny shower but I've adapted. When in 15 degree weather....loved the heated mattress. When in 100 degree weather....loved the ducted AC. I just retired and after Christmas I'm heading south and west. Enjoy your new toy!
IBEW LU 613 Atlanta
Micro Lite 21 FBRS