This is solid advice hereIf he is leaving the quarters on the bone then he most likely is hunting Alaska and it is in unit required to do so by law.
No way you’re getting away with four bags and extra for loose meat.
You need bone out both sides of the chuck, that’s two more bags right there. You will need to take out the ribs as well, split them and leave the brisket on, another Bag for that…..your up to 8 bags, don’t forget your back straps and the cape if your taking it.
Last moose trip in Alaska it was 5 trips with two of us to get it all, the rack comes last.
Don’t forget to take pictures of the remains of the carcass it makes it easier if you get checked by fish and wildlife. They will nail for wanton waste if your weights don’t add up.