I use a LowePro flipside 500AW.
Carries 7D2, 10-22, 70-200f2.8, x2 extender, mavic pro x 3batts. Extra camera batteries, filter pouch on the side, mini flask, water bottle in side pockets. Hat n gloves, two head torches, more batteries in front pocket.
Strapped to top in a drybag is large...