On the topic of the Arctic package, the 2007 brochure has on the rear page a section titled "ZERO DEGREE - Tested and approved features enhance four-season living" and then lists
- Vented Attic
- Enclosed heated dump valves
- Enclosed heated holding tanks
- Insulted water lines along furnace duct
- Digital Thermostat
- Heated Stool room
- Arctic insulation package with higher R-values
- Enclosed low point drain shut-off valves
- Fully enclosed underbelly ABS
Of interest that is the only place that mentions Arctic insulation package - and it appears to be a standard feature as the Optional Features start right after the Zero Degree box. Dual pane safety glass windows ARE listed under Exterior Options.
Anyway, Sure sounds like we should expect to be able to camp in "cold" weather!