FWIW, I checked into Verizon's plans before sending him off, and they've got a $15/month adder that gives 100 mg, 100 minutes, and 100 texts, then .10/min after that. I figure that's probably about as good a deal as signing up with something locally. And it looks like Verizon's got decent coverage around Gillam.
I have warned him to ration his calling and texting (sorry, kids!). :-)
If there are coverage issues, he'll be back in Winnipeg for a couple days and can pick up a local provider's phone then.