I will be bringing at least 4 batteries i have the battery grip for my 5d mk3 and will hopefully keep enough charge in them to last the trip.I would leave the grip at home an just bring the batteries. Your back will appreciate the reduced weight after a couple of days.
Ditto! And it sounds like this isn't your first rodeo but I would have a comfortable side sling strap for when in camp and not hiking. The cotton carrier is overkill when it's not needed. It might become a nuisance. But of course, whatever works for you is best. Have a great trip!!