The cruise lines will require in most cases a 90 day in advance of the trip, full payment. You don't have much time.
If I personally was going to spend more time over there which you appear to want to do, I would cancel the trip before the Line gets my money and I have to deal with getting a refund. June is not that far away, and countries keep changing the rules on Covid-19.(as do the cruise lines)
Others may feel differently from me about cancelling your June trip. -Tom
Unfortunately, we’d fully paid for a trip in 2020 that got canceled. Including 5 nights in Prague. At least we bought trip insurance & we can get back that hotel fee & airline tickets we can’t use. I’m sure Viking will allow us to use our funds somewhere else. They have a Mississippi River boat being built. Maybe we’ll do that instead.
It’s all just so annoying that every gov’t is pretending that covid is the Black Plague again. Sheesh!