For remote trips we always have a small "grab bag" which is a soft insulated lunchbox that has:
SatPhone with NextG SIM, simple mobile phone with a charged battery kept separate to the phone (no SIM but can use the same one as the SatPhone, compass, flint, lighter, marker pen, pencil, notepad, dynamo torch, band aids, pocketknife, chargers for phones (12v & 240v), 600mL water bottle, signal mirror and a disposable poncho. Always reachable in the vehicle and easily fits into a pack for walks. Add any essential medicines if you need to.
Hoping to never use it in anger but as I've done most of the really remote trips with just my middle son since he was eight, it's comforting to know it's there. I've reached for the bag a couple of times just to make sure it's there when things got a bit hairy. My son knows how to use everything and we run through the SatPhone startup at the start of each trip.
A good first aid kit is also easily accessible.