Can Pod be set up for use in winter

You don't have to "only" dry camp. It's easier and cheaper but I used mine to go snowboarding and had water so...it'll do winters BUT it costs some money (tank heaters).

The R-Pod needs some fairly extensive mods to do winters BUT once you do them its a really good winter camper because of the extruded styrofoam walls.That is the first point.

The R-Pod, for all its faults, has (IMHO) very good construction for winters...here is why. Your normal RV in this price range has wood walls with regular "fiberglass" insulation which will fall down/degrade an collect in the bottom of the walls. The R-Pods walls are an empty frame which they extrude styrofoam into giving you very good and uniform insulation. So..there is that :-)

Mods that are needed/I did to mine...plus a couple of extras.

0. Tank heaters, elbow heaters, pipe heaters. Thing is you HAVE to be careful because the RPOD power supply can only source so much juice. So do the power calculations. I had a complete package installed and I only ran the freshwater and the fresh water hose heater (keep reading). We flushed the toilet with RV antifreeze and the same in the Grey tank....used a lot of RV antifreeze...but it's pretty cheap and its not that big of a deal to do.

1. Replace the garden hose...yes garden hose! The freshwater tank has a GARDEN HOSE coming out of the top that feeds the pump. Yep..it'll freeze and split like crazy. Replace it with a pex hose and AND wrap it in the smallest pad heater you can find (I used Ultraheat). Works great.

2. Buy a case of expandable insulation spray foam and FILL THE HOLES. First time I used the RPod in the winter, the heater ran almost continuously and you could feel freezing air pour in. Not so bad in the summer, not good in the winter. Here is a list of the holes I filled.
 - Behind the fridge, there are open seams, in the winter, cold air pours
            in around the fridge and I mean POURS. Remove the outside cover, fill the gaps.
        - Under the sink - When they build these things, they cut about a 2 inch hole to
     install a 1" piece of PVC. Under the sink, where the water hose comes into the
            pump...hole...fill it.
        - Under the sink, on the wall, you'll see the back of the outside electric and cable
            outlet. It's pretty much a thin piece of plastic between the inside and outside.
        - Under the seat (where the water heater is) there are some cut outs for the water
            fill etc... spray foam em'
        - Under the shower...I saved the worst for last. There are at least 4 pvc pipes under
            the shower. In my pod each of the holes were about 1.5 times the size of the
     PVC an cold air POURS through them. These were so big, I used some screen along
            with the spray foam. How to get to them? I took the small vent off the front, but
            could only get to a couple of them. So I cut a hole in the wall, very near the
            floor, under the bottom bunk. Spent a couple of hours crawling and worming
            around, and filled all of them.

****Ok thats the basics...here are a couple of extras that I did to make it REALLY toasty.
 1. Bought a sheet of 1" pink styrofoam insulation and cut pieces to place
             on the floor. Then bought the Rpod rug from forest river to cover them.
             REALLY warms the floor up and they don't "squish" when you walk on it.
        2. Bought sheet of 2" pink styrofoam and lined the hidden walls
             (even under the bunk). So I lined the walls inside the cabinents, both floor
             and ceiling, under the bunk, under the seats in the storage are and where
             the water heater is, and under the bench seat where I cut fitted pieces
             and installed them through the storage area below the seat.

Wheww....lots of work....but the result. 2 years ago, camped over winter holiday break,
         at 10,000 feet in the Rockies. Cold blowing wind...warm as toast.
         camped 11 days and used 3/4 tank of LP!

It takes some work...but the RPOD makes a very good winter camper.