Wow, thank you for that. I have some experience with the TI switchers and your circuit looks like a great approach. I just looked at the Datasheet for the Boron and realized that none of the pins are 5V tolerant so your suggestion for a voltage divider is a very good one.
I do find the TI QFN with powerpad somewhat painful to solder so I am open to other options. But, this chip seems perfect so I will layout a board once I validate the approach with the Pololu module.
As for the stuck with 3G part, have you tried the Electron LTE?
Thanks,
Chip