Sounds like a static location scenario. Moving around, less than optimal weather, etc, will impact that. Weight is also a consideration: how heavy is the solar system compared to battery packs, how long are you out for?
I was away for nine days in April and seven days just last week (Highlands, no access to power throughout). On both trips I easily maintained charge on my phone and Bluetooth headphones with an old Ravpower 26800mAh battery pack weighing 484g. That was using the phone for navigation on downloaded OS maps in aeroplane mode (never really used the paper map backups I was carrying); also used it as my camera, podcast player etc.
So it’s really a case of assessing your priorities and needs. I’d err towards battery packs, personally.