Bought a 20L alpkit bag and tested if everything fits:
Had to put 3rd strap in the middle to prevent tire rub (limited space between tire and bars because tiny frame), but other than that it takes all the essentials \o/ (bivi, sleeping bag, pad, cooking stuff) with room to spare
My fork doesn't have a brake hole, but neat idea. I would consider rack if i were carrying this stuff more often, but it's mainly a road bike and i do one-nighters once in a while when i'm not too busy with dad stuff
e: though i could go with something minimal like this:
Bought a 20L alpkit bag and tested if everything fits:
Had to put 3rd strap in the middle to prevent tire rub (limited space between tire and bars because tiny frame), but other than that it takes all the essentials \o/ (bivi, sleeping bag, pad, cooking stuff) with room to spare