There are a number of convertible backpack panniers.
The most elaborate system is the Richard Jones system.
https://pannierbackpacks.com/
I've been dreaming about that pack system for a few years, but have no idea how well it actually carries.
However, there are numerous "Day Pack" panniers that would be good for shorter excursions. Or, perhaps reduce what needs to be carried.
One of my concerns is bike security. I haven't tried these panniers, and I really don't want to leave my bicycle overnight at the trailhead. However, I'd probably carry the bike up the trail, maybe 1/2 mile, then off the trail a bit, so it is out of sight from both the parking lot and the trail head, and lock it to a tree.