I'll start with the gross generalization that IMO one can't have too much rooftop solar panel capacity if planning for off-grid adventures.
Given your stated long-term aspirations, I'd carefully consider the solar panel options offered by ETI. Think and investigate carefully all that's involved with adding rooftop panels in terms of costs and efforts whether DIYing or having a 3rd party do the work (the latter can be eye-popping for truly competent work).
IME (BTDT), the work involved in adding rooftop panels can be 'sporting' on many fronts. Not saying it can't be done, obviously many of us have with good / great results, but it presents a different and IMO generally more difficult set of challenges than all of the much easier 'interior' equipment upgrades you mention.
The ETI solar panel options are not inexpensive, but they
might be a
good value in the long-term big-picture for
you (only
you can determine that).
Just for your consideration, Have Fun!