Flying from SLC to Warsaw with a 6hr layover in Amsterdam. I will be returning to Amsterdam two weeks later to join a river cruise. Can I claim luggage in Amsterdam from the first leg of the flight, store it at baggage storage and retrieve it when I return to join the river cruise?
It is possible. This is called short-checking. You must request it at the check-in counter but it is at the discretion of the agent that serves. Usually, they are reluctant to do this for a short connection but 6H is plenty. You may have to explain yourself to convince them but if you have the confirmation from the cruise I would expect it to be considered a good reason.