Solar power

Presuming the OP has enough battery to get by, I would think 60-80w would suffice... just enough in winter, more than enough in summer. Amorphous work well in all light conditions, but are bigger and heavier. Monos have the smallest footprint. As others have pointed out, a 100w may be the same price or even cheaper than a much smaller system. Either way, you're gonna pay more per watt, the smaller you go, and much more for flex panels.

Here's an Ebay listing for an 80 watt kit:

http://www.ebay.ca/itm/161404064086?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649