I use the Kinesis (kgear.com) modular system: L511 and 500/4 w/ hood reversed & camera attached closes easily; with hood forward you would need the next size up to close, though you could still carry it open (and I have - get's dirty and wet, though). I add various component bags for 200/2.8 & 400/4, tripod & gimbal head, other gear, with or w/out pack frame, all clipped together as needed.
It takes a bit of research and trial & error to get everything right, but very well made trekking gear. The pack frame is the weakest link, tolerable only for a few short days (but who can carry 20kg of camera gear for all that long?
Nice company to interact with. No problems exchanging some pieces that didn't work with my gear. They even did a custom belt-loop for a collapsed monopod, so I could walk with the 500mm in shooting position comfortably (works well for ground animals, not birds). Carried 500/L4 to Africa, Asia, S.A. and all over N.A. over the last 5 years with no issues, no bag failures.
I have no affiliation with Kinesis other than as satisfied customer. I have not bought anything for several years, because it's all still working fine after 5 years of regular use (I do tend to be very easy on equipment - YMMV).