You'd have to ask permission to leave the car and it's up to the resort if they say yes. I can't say I've read any reports of the resort saying no in the situation of using the DCL transfers, but some of the resorts do have very limited parking so it could be an issue. Personally, I would just drive to the port. With the DCL transfers costing $35 per person each way and parking being $16/day, it's hard to come out ahead using the DCL shuttle unless you are a single person on a 4 night or longer cruise.
As noted, it's up to the specific resort if they'll let you. Recently someone posted that, after contacting their resort, they were told that "no, they are not allowing vehicles to remain on the site, if the owners are not there". Speculation was due to recent international events they aren't doing it any longer.
It's best to call your resort and ask.
May I ask why, though? DCL transfers run $35.00 per person each way. And, unless you are staying at a resort after the cruise, I don't think you can take DCL transfers to a resort.
Driving yourself, and parking might be a better option.
So you're looking to drive to a WDW resort for one night prior to a long cruise, park your car, take DCL transportation to port and cruise to either a European or west coast port?
How are you planning on getting your car at the end of the cruise?
How are you thinking to get from MCO to the resort? I don't think you can take the Magical Express unless you have a reservation.
I'd suggest long term parking at the airport as a possibility. Maybe stay at the Hyatt MCO before catching the DCL transfers to the port from the airport.
The problem is OP is contemplating a TransAtlantic or Panama Canal cruise. Both of which will not return to the port. That's why I suggested parking at the airport, and using DCL transfers to the port from there for the cruise. Then the car will be at the airport when they fly back home.
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