2) I haven’t spent very many nights in full on winter conditions (that 12 degree night in Boise comes to mind!), so I can’t comment too much. It was fine for that… Mostly it was hard transitioning from the warmth of the cab to the frigid air while you are shifting things around and getting ready for bed, but then once you were inside the canopy it was fine. Lots of frosty ice on the inside windows, but in my sleeping bag all was well. It stays a little warmer in the canopy. Maybe I’m a wuss, but I didn’t want to spend an extended period of time dirtbagging it in my truck while I was ice climbing (I spent the first two months in Ouray, CO, sharing a rental), I just thought it would be too challenging/miserable to dry and manage gear in a confined space with the shorter daylight hours. I’d be perfectly content doing future weekend trips with this setup though!
When I built my shop I opted to buy a much higher quality miter saw and table saw than I truly needed at the time. It ate up a ton of my budget and forced me to put off adding the tools that would allow me to buy cheaper stock for 2-3 years. During that time my savings buying rough cut lumber would have probably paid for the upgraded equipment I started out with.
Expanded polystyrene (EPS) is an open-celled foam board (think styrofoam) that is the cheapest of all the foam boards. It does work, but we generally don’t recommend using EPS in your van. It insulates less than XPS (R-4 per inch), and the gaps between the foam cells allow moisture to penetrate, which degrades the insulation over time. Polyiso and XPS are much better choices for a slightly higher cost.
In our opinion, having one of these is an absolute must for living on the road - especially in humid areas. To fully cover the width of a van’s side doors/back doors, you’ll need a larger screen that’s designed for French doors. If your vehicle has a smaller door opening like an RV, a screen meant for a standard door will work fine. We could only find standard door screens, so we bought two and hot-glued them together to cover up our side door.
The refrigeration setup in your van is an area where you really do get what you pay for, whether you’re paying in money or in time. The best options are the most expensive. The cheapest options are a pain and/or don’t work very well. And if you try to save money with a DIY refrigerator setup, you could end up spending a lot of time on installation.