I agree with those stating that your best bet is to roll it to 2023 when it's quite likely many of these restrictions will be lifted. No one can predict the future, but 8 weeks ago Viking still had daily testing onboard, and quarantined people off-ship if they tested positive. And now they don't, and I don't see it returning, no matter what new variants arrive - the public will just isn't there for it.
However you also have to be mindful about the rules for the countries you are visiting - for example, on paper, the Netherlands (where we flew into a few weeks back for our late June cruise) requires proof of vaccination to enter, and they do not make exceptions for religious objections. However, in practice, the lines were so long and they were processing people so quickly that we walked right through customs without them asking anything...they didn't even ask to see the "mandatory" Netherlands vaccine attestation form that it said we had to print out. But they COULD have asked, and there's always the chance they do it like a random sampling thing, and if you get asked at customs, you may be turned around last-minute.
But I simply don't see these requirements lasting into 2023. A number of EU countries have actually dropped vaccination requirements (I guess it's always possible as a last resort to fly into one of those).
We just returned from a Viking cruise; they don't care right now. People can be coughing and sniffling up a storm; no one will be asked by the staff to take a test unless they specifically ask for one. And no one does because they don't want to be quarantined. It's every individual for themselves.