AT&T

Name: International Day Pass
Amount of Data: from your current plan
Speed:  LTE
Cost per day: $10/day + $5/day for each additional line
eSim cost per day*: $1
Gotcha: High Cost

Summary
$10 fee for one line gives you coverage for 24 hours. $5/day for each additional line on the same account, used the same day. Access to your data, so no need to hunt for Wi-Fi® while you travel Unlimited texts to the world. Unlimited calls to the U.S.

Some links for International Day Pass ATT
https://www.att.com/ecms/dam/att/consumer/upperfunnel/2018/pdf/Travel-Tips-IDP.pdf
https://www.att.com/international/day-pass/

Data
The data will come out of your existing bucket of data allotted to you from your current plan.

Calls and Texts
Both free. If you’re in an International Day Pass country, you can call the country you’re in, any other International Day Pass country and back to the U.S. for no additional charge. Calls to countries not included in International Day Pass will be billed at International Long Distance rates.

Summary
Certainly better than Verizon but still expensive for a multi week stay in Europe. Our solution, keep your current line and get an inexpensive eSIM!