That's a problem that will solve itself as CDMA gets shutdown in favor of LTE. https://www.fiercewireless.com/wireless/updated-verizon-wire...

We're already seeing this transition happen in other markets - in Japan, while KDDI is still running their 3G CDMA network, new iPhone models are not being provisioned to connect to it, using solely LTE (thanks to the LTE coverage being superior as they can use the low spectrum freed up by analog TV).

What does LTE-only coverage look like on Verizon? Do you miss out on much if you pop a Verizon SIM in a device without CDMA? And do they support VoLTE?