Originally Posted by LtKernelPanic

I'm leaving for a 2 week trip to Europe next week and will be primarily in the UK, Germany and Poland. I currently have an iPhone 13 Pro Max with my AT&T service on a physical SIM and plan on using Orange's 20GB Europe Holiday plan while traveling on an eSIM. I'll be starting and ending my trip in London if it matters. That said I have a couple questions.

1. Can/should I install the eSIM before departing the US or would I be better off just installing and activating it once in London? From their FAQ it looks like I can install it before leaving ad once it recognizes a European carrier it will automatically activate. I just don't want to do something that could cause it to activate in the US because I'll need all 14 days the plans offer as my flight home will be on day 14. I'd like to have it installed and working before leaving LHR but in a worst case scenario if I could wait until I get to my hotel. I've stayed there several times and know how to get there.

2. I've seen it mentioned several times that you can enable wifi calling, turn off roaming on your US SIM and use the data from the local SIM to make and receive calls to/from US numbers as if you were in wifi. Is that all there really is to it? I have a Google Voice number that I know I can use over cell data to make and receive calls and texts to the US if need be but I'd rather just be able to use my existing US number since that's what all my friends and family already have.

I'm sure I'm over thinking things as usual but thought I'd ask before doing something potentially stupid.