Unfortunetly,as stated in the terms and conditions of this promotion,you can't exchange in into cash,even if you are a local.The only cash you will get are the 250 €.
Terms & Conditions
No cash alternative will be offered if players win a package but do not require hotel accommodation.
Then you can use the hotel. It's part of the package. If you want the full experience, accommodation would probably be best.
You can use the hotel for sure.If you win this package you'll get acomodation included.
Players will stay at the luxury-grade Marriott hotel and will be treated to the famous Unibet hospitality, including welcome drinks, players’ party and lots of activities away from the poker table,so why not indulge yourself for a few days? :P
More details here :