Just had a memorable three day bikepacking trip on the Sunshine Coast in BC. I cobbled together bags by borrowing and hacking some bits and whilst it all worked, it wasn't quite perfect. We took bivvies and a tarp which worked pretty well, and in summer will probably be able to ditch the bivvies and just take a tarp.
A dropper compatible seatpost bag would be good to replace this borrowed Apidura one, and the bottle on the underside of the downtube didn't really work as the nozzle got filled with mud.
I'm considering a custom frame bag as there are some cheap local makers, and probably a food pouch, but still haven't figured out how to store water if that was the case. I'm also wondering about trying to strap some cages to the forks, but without mounts that could be a recipe for disaster. Would welcome suggestions and thoughts about options.
It's amazing how different it feels to cover distance on trails as opposed to road or gravel, our longest day was 43k with 1300m elevation and it took almost 6 hours! The feeling of grinding up hills in the biggest ring on a laden mtb is so different to climbs on a heavy gravel bike, but the downhill trails are definitely a big reward for the effort.