With a built in generator and solar and being that you really won't have much of a draw on the batteries for hogs like heat you should be fine. A test before is a good thing but even if they are not 100% I would not worry.
From my emergency training side of things....
- Toss in some extra fuel as if power is down you will need it and if it is not down chances are the prices will be up.
- Take a good extension cord with you as if it is as bad as they say you will be the power company in your neighborhood maybe for a long while!
- Another thing to toss in is a can of flat repair, going into a disaster area you will not believe the nails and sharp objects and just when all the shops are closed!
- Top up your water and maybe carry extra with you. Those stupid collapsible water jugs (the ones that leak if the are not upright) are great as you can fill up before you hit the bad area and if not needed they fold down and take up very little space!
Drive safe and all the best!!