I have been through that experience at Eglan Florida and can tell you that staying dry and fed is the key. We were so wet and cold that we just shook for 10 days even though it was only 45 degrees. I was more comfortable at 10 degrees when I served on the DMZ in Korea. I routinely hump the following if I'm going to be any distance from our camp. I figure worst case is either an injury or a down elk that requires an overnight stay. Rather hump it than be without. You just get used to humpn the ruck and consider it part of the gig.
One Green Arc Teryx Ruck with 2 quart bladder.
Army Goretex set
Extra set of seal skin socks
Polypro Balaklava and extra glove inserts
Army goretex sleeping bag cover
One ultra light 3/4 length therma rest
One poncho liner
550 cord
one or two MRE
usual crap like knife, lighter, compass, GPS, topo map, folding saw, pogie bait, handi wipes, trihex heat tabs, 10 -12 rounds of ammo, steiner 8x30 binos, one laser RF, one weapon
Conrad101st 1/503 Inf., 2nd ID (90-91) 3/327 Inf., 101st ABN (91-92)