After reading this thread, I've been experimenting with putting my phone in airplane mode and using RideWithGPS for navigation. My first 2 hour ride looks promising.

https://www.facebook.com/groups/5247...9102172548564/

I found a cheap pre-paid phone that I might purchase if it looks usable. Then I can keep my regular phone on and ready to use... plus it makes a good backup.

Failing that, I've been strongly considering the Garmin Edge Touring. I'd read some bad things about the GPX navigation though.. being a bit tricky to set up. So if the solution I already have works, I'm going to use it