Thanks to some good advice from he11o_sunshine, I called my credit card company yesterday and let them know that I would be out of the country for 3 weeks and that I would be using my credit card in a variety of places in Europe.
They were very good about it. They took down the dates that I would be gone, and told me that information would be factored into the algorithms used to determine if possible fraudulent charges are being made on the card. So I shouldn’t have to worry about my account being frozen while I am gone.
Thanks, Jen!