If you have a dual-SIM phone and your primary plan supports Wi-Fi calling, you don't even need to "roam" on a different SIM. You can use a local SIM card as your data plan and route your calls and texts over that network. There are a few iPhone apps I've used that allow you to download an eSIM in a couple minutes for five bucks.
I think all of them since the XR/XS era, 2018 ish? My iPhone 13 mini does dual eSIM (I used both AT&T and T-Mobile when I was in a remote area and it worked great).
