Thanks for the replies everyone! I was thinking I would shoot for 400 watts minimum of solar. More curious how easy it is to get 400 watts on such a small roof. Probably isn't easy based on the size of panels. I was looking at 250-280 watt panels which are larger than the 100 watt panels (of course), but it actually might be easier to fit smaller, lower output panels on a small roof so this gives me some ideas.
I'll see if I can get on the roof of one and see what available areas I have. If needed, I could always try and install as much rooftop and then make up the rest with a portable setup that I would deploy in the mornings and stow before heading out. Second concern will be where to store batteries. I'll likely start with lead but move to a self-built lithium battery eventually.
Microwave use is not an important requirement compared to all the other things I would like to be able to run, so optionally I can just plan to cook with propane instead in trips without shore power.