Cell Phones

Don't know what the Verizon add-on costs to use your existing phone # in Europe. To use a sim card means that your phone operates on a different phone number, at least that's the way mine worked the last time in bought a sim card in Europe. The advantage to an add-on is that you can use your phone operating with your number. Otherwise you won't know if family, business, airlines, hotels, venus and friends are trying to get ahold of you.

Depends on what you need to do with your phone while away. With the Verizon package, you keep your same phone number, so receiving calls and texts remains the same, plus x amount of data. Many esims are data only, so there is no phone call ability, unless you have WhatsApp calling or something similar. There are esims with both phone and data, but it will be with a different (European country) phone number. Calls to your regular phone number would not connect to you while using the esim.

I always get the Verizon monthly international plan and my phone works just as it does at home. Make sure you have roaming turned on.

Easiest is just add Verizon's TravelPass. Or, they have a $100 monthly travel plan. ( https://www.verizon.com/plans/international/international-travel/ )

TravelPass
$12 /line per day. Plus taxes and fees.

With TravelPass
Get unlimited talk text and data in 210+ countries and destinations.*
Once added, you'll only be charged on the days you make or receive a call, send texts or use data on your device while abroad, so there's no need to remove it when you return.
TravelPass can be used in 210+ countries and destinations.
If you choose not to add TravelPass or travel to a country not included in TravelPass you'll be charged Pay as You Go rates.

International Monthly Plan
$100 /line per month. Plus taxes and fees.

*What’s included:

Unlimited data (After your first 20GB of high speed data enjoy unlimited 3G data.)
250 minutes
Unlimited texts
Overage: $0.25/min

Calls to your regular phone number would not connect to you while using the esim

Doesn't your smartphone have the 'Dual SIM Dual Standby'-technology?

This is rather common in Europe, no idea about USA. With this technology you can just stay connected to your regular phone number and use the esim during your vacation abroad.

We have Verizon and just upgrade our plan to Unlimited Ultimate while we’re gone. You can then simply return to your welcome plan or whatever you have when you get home. This is MUCH cheaper than paying for an international plan with them. In our case, it’s about $30 for two lines for the month and it’s unlimited data.

Verizon had a dedicated international help desk awhile back, and the people seemed to be very knowledgeable and helpful. Not sure if that is still the case, but perhaps getting an answer straight from Verizon will give you the best answer. It's at least worth a call.

The number at that time was 1-800-711-8300.