Toggling phone numbers on iPhone 16 Pro Max for international travel

I will be traveling overseas in the month of Jan/Feb and want to use a local number in the country that I’m located. I also have a number in the U.S. that I can deactivate with the carrier but would prefer to shut it off on the phone so it doesn’t connect to a local tower in the country I’m traveling in. I would want the option to connect back to the U.S. with my U.S. number for my own purposes but I don’t really want that every day so I can control the costs of this expense. Is there a way to toggle this phone number off and on and still have the phone active with the other phone number?

[Re-Titled by Moderator]