Do you recommend an eSim like Holafly to for basic data usage when wifi isn't avialable - maps, apps, iMsg/SMS, etc?

What do you recommend for calls?

Should I set my AT&T to allow international calls, but enable an eSim for all data?

If so, is it easy to delineate in the iPhone that data is the new eSim, calls the original eSim?

I don't intend to make calls when in Europe, but what if family needs to call me for an emergency (or vice versa)? Buying a local sim card would require our families to temporarily use a different # to contact us. Hell will freeze sooner than they could manage that feat.

When my company paid my bill I just told them when I'd be in Europe, they'd add international, and I gave thought to usage. Now that I'm footing the bill I want to find the most economical way to not wonder what using our phones for XYZ is going to cost.

It will be my wife and I and we're on the same AT&T plan. I know I could forego the eSim and just rely on wifi access for any data needs but I don't want to have to think about it.

Have used giffgaff.com for data only SIM.

I used Holafly for data in Italy and Switzerland this past month. It was easy and it works well for Texts and sending pictures, using Google Maps. Unlimited data.

I'm on Verizon at home . If you need to make a call, flip the virtual Sims back to Verizon. You will be instantly charged $12 a day. Flip back before the next day if no calls are needed.

While you are on Holafly, people can't call you or text you at the US number. Best way to get around this is to Text people back in US first and tell them to reply to this text if they need you.

Depending no how long you're going to be in Europe, I'd just pay for AT&T Day Pass. Similar to the Verizon mention below it's $12 per day for the first line and then $6 per day for each subsequent line. You'd need to make sure International Day Pass is enabled on each line in your account.

Making sure your phone is configured appropriately to use an eSim and not be charged for the AT&T day pass is something to double check. It's easier on iPhone than Android, but there are specific settings that need to be configured. Here is one thread on how to do that: Reddit - iPhone eSim.

I used Airalo on a recent trip and didn't have any issues. They also offer one day free in some countries if you want to test it out.

Just do the day pass $12 a day for unlimited calls and data.