How much do you want to spend?
Today I purchased the new DJI Action 3 (adventure bundle) to use as a rear camera since my Drift was pretty much DOA.. It's pricy but the adventure bundle comes with 3 extreme batteries and a nifty and compact case to hold and charge them all on the go.. Battery life will depend on settings etc but with 3 extreme batteries you should be able to make it just fine. Even more so since when you replace a battery and put the dead one in the charge case, it will charge it back up. They claim it's fast a charging battery pack and you can get 80% battery life back in all batteries in 56 minutes. Basically you'll never run out of battery.
This review is pretty good on the setup. He talks about and shows the battery charging pack that comes with the Adventure bundle.. He talks about the battery pack at the 11:20 mark of the video.
The DJI 3 adventure bundle is $439. But it comes with 2 GoPro mounts so I can keep one permanently attached to my bike then have another mount for when I want to use the camera for other activities.
If you don't want the adventure bundle the the standard Action 3 sells for $329.. But for an extra $110 with the adventure bundle you get 2 extra extreme batteries (3ea total), the portable quick charge battery case, 2ea GoPro mounts, and a selfie stick. I'd never use the selfie stick but the extra batteries, portable charger and the extra GoPro mount was worth the added cost to me..
I guess it all depends on how much you want to spend. I looked at the new GoPro's, including the Mini after GoPro's announcement today and opted for the DJI over them. For me 3 included batteries, quick charge portable battery pack etc was my deciding factor..
Good luck..