Since you're still going, I did Strava home with the cell reception turned off
Bike Ride Profile | Afternoon Ride near Alpharetta | Times and Records | Strava and it worked like normal.
njkayaker has been wrong with just about everything he's said about the Centura phone, but I think he's more or less right that in general only a cutting edge phone is going to have BTLE support.
Options for avoiding data plan are all relatively recent. You've got pay as you go, a few options that I've listed, and that's it. Except for AT&T paygo and Straighttalk all of them appear to use the Sprint network. I'd do the Moto-G with Republic, the $10 no data plan which is what you're asking for. If you don't like the coverage it's back to Straighttalk or Tracphone (which is Verizon, not "some weird network" as someone described it). If you choose Tracphone, it's the Centura, a couple of lower end phones and another of about the same caliber.