We bought our 4 Season Lance 1685 a bit over a year ago. We looked at Arctic Fox and Nash as well as others, but they were both too heavy for us to tow with our Toyota 4 Runner. We camped in our Lance from March - May 2015 in the desert southwest -- snow 6 days and temps in the mid to low 20's several nights -- with no problem, love our little trailer. No experience with anything colder or with longer than a couple nights at a time. The rest of the 3 months was generally upper 30's at night. Daytimes were always between upper 50's & 70's.
The Lance is lighter than the other 4 Season trailers we looked at ... also has 45 gallon tanks and dual axles which was a plus for us.