Making Phone Calls from a Different Device
If something like that should happen, you can just get your carrier to "port" your phone number to a new SIM card, and use that in the replacement/spare device. This is more or less the same process you use to transfer your number to a different carrier, but a lot simpler in this case. After all, they're the ones in control of what phone number goes with what SIM. Ask the carrier for a replacement SIM and they should be happy to oblige.