ps if you can drive to a place with a signal you can get them to send you an SMS and then check a couple of times per day. The SMS will be received when you gain a signal.
You may not even need phone signal to get a SMS in?
We've just had a few days out at Cullendore on NSW / Qld border near Warwick & Stanthorpe, & needed to make a phone call one day. Turned phone on in camp - no signal showing, couldn't make call or get internet access, but almost as soon as I turned it on, got a spam SMS in! Drove up the top of the hill & showed 3G (Telstra) with no signal bars but was able to make necessary call.
Back down to camp & tried to check weather that pm but no access - but eldest son spent the next 2 days on his bloody phone with texts to & from his mates
Turn that bloody phone off & put it away! Sure thing Dad. 30 min's later, sitting surreptiously tapping away on the phone sort of hidden on his lap ...