The reason they closed the monorails and other Disney transportation is because of the park capacity. Staying in a Disney Resort guarantees being allowed into the parks even after they've reached capacity.
When I was at the World for New Year's Eve we went to AK in the morning, then wanted to transfer to MK for the celebration. We had one CM tell us that MK was closed, but another told us that they were probably told to do that to divert people to the other parks.
Anyways, considering they would be trying to leave the parks, not enter them, it should not be a problem to use Disney transportation to get there. Then, if for some reason EPCOT or MK reached capacity, they would only have to tell the bus driver that they were parked there, and I'm pretty sure the driver wouldn't refuse them transportation back to their car.
Either way... the OP would be able to take a bus from MK or a bus/boat from EPCOT to get to Beaches and Cream.