RE: Solar
First, I don't understand how you are going to replace the use of propane
with a solar panel, at least that's the way I read part of your post.
As for the foldable/rollable/flexible solar panels the flexible panels are
much more expensive than the conventional panels, much more for the same
capability.  And the flexible panels seem to only be available in smaller
sizes.
As for the GoWesty setup. a 50W panel, at $649, less than a month ago I
bought a 50W panel for $179 including shipping to my home. The controller
they include is under $50 and the wires and connectors can be done for $20
or under. A 50W panel, under ideal conditions with a good controller, will
put out about 2.6-2.8 amps.  Assuming a really good day with bright Sun for
eight hours that's less than 24 amp hours of current.  That's fine for
moderate use but you really need to figure what your electric consumption is
going to be and then figure out how much solar charging capacity you will
need.
Several people I know have their solar panels mounted on the roof and are
happy with the results.  But I've never talked to them about how careful
they are to park with the panel pointed south for maximum charging.  I do
know, from watching the current flow, that the angle to the Sun makes a big
difference in the output from the PV panels.