You can manually unlock the other three passenger doors from inside, using the little individual slide-latches by the release handles. The rear hatch and window really need power to open. The hatch lid can be released manually from inside after you pop the little access panel out. Your owner's manual has detail with pictures of how to do that. You won't be able to open the hatch glass when power is lost, short or removing the hatch liner and manually releasing the window latch.
One of those portable jump-start boxes might be a handy addition to your travelling arsenal of tools and toys. Probably best to not store it under the deck in the back, though.
Our Pilot sees intermittent duty at best in all seasons but winter. Now with CV limiting a lot of social and cultural interaction, it sits even more. So it has a good battery maintainer connected while it's in the garage, so the battery doesn't drain between drives.