This is with us to stay for life, so I would not put too much thought into it for something so far away in the future. As they say, 'cross that bridge when you get there'. European countries do enact a lot stricter rules compared to the United States, and do so at the drop of a hat. The difference I see is that their healthcare system is not based on profit, so it does not cost so much, or anything to constantly get tested. My family is there, and though you don't read it in the news papers, or hear it on the news, they quietly blame foreigners for their rise in cases. They just don't say it openly because it makes them look bad.
For what it's worth, in the summer we planned a Christmas Market tour in Germany. We had done this with the kids when they were very young, but now as teenagers, we thought we'd do it again. My wife and kids are already in Europe (Norway), so I was just going to meet them in Germany. We invited friends to go with us, and we were all very excited... this was August. By September, we saw cases started to rise in all of places, Germany. They kept rising, and rising and by October, we knew there would be a spike in Europe and knowing how Europe imposes lockdowns quickly, we thought we'd be on the safe side and cancelled our trip. Not because of COVID per say, but because we did not want our friends to be disappointed. And they were that we cancelled. They even offered to miss some of the markets, but we told them once Germany starts to shutdown, everyone will follow. One by one, the cities started to announce that they were cancelling their markets. I knew the nail in the coffin would be the Nuremburg market, and sure enough, it too announced they would cancel just after Thanksgiving. Even the cities that said they would have "something", are now announcing nothing in light of the lockdowns. Germany, Austria, The Netherlands, and on and on have now implemented lockdowns so that you cannot even go and enjoy the cafes and restaurants normally. All that said, I think that after Spring, things will start to get back to normal for your summer trip.
Now, for some unsolicited comments... not everyone believes in a God... I do, and my God did not put me on this planet to live in fear, and so I don't. Of course, I take all the precautions, but I do not live my life by COVID as one lives their lives by a clock. Just do what you would normally do. If everyone did this, the world would get back in order sooner. People need to get vaccinated when they feel like it, not forced to, but also need to accept the consequences of not being vaccinated. Other than that, there is not much you can do to control what happens around you.
The other alternative it not to go anywhere, never have a vacation, stay home, order groceries from a delivery service, and always be constantly in fear. That is not that way I'd want to live my life.
And one more thing, by now most people with at least a sixth grade education know MASKS DO NOT WORK! I wish the world would stop playing this charade. If you can smell anything through your mask, then the virus can pass. If you can't smell, get tested because you may have COVID!