Almost everything is backwards compatible, that detail is what impresses me the most.

If you want to get apps you've already downloaded, the only way I know how is by using the Google Files app.

I download all my apps through Obtainium. There may be an easier way than this, but I use all the URLs from the Obtainium export file to go directly to the .apk file. I do this quarterly. I don't use very many apps, so its not a long process, even if it is manual.

I've been saving all the .apk files for apps I find valuable, just in case this ends up impacting future GrapheneOS builds.

Worst case scenario, at least I'd be able to use a saved Pixel for the apps I want, without needing a Google account.

There's a product called the GoSun EV Solar charger, which also promises to add 20 miles of range in charging daily. It's on preorder, and I'm waiting until reviews come in before buying it myself, but I'm hopeful.