We recently made a 7-day Atlantic crossing on the QM2 from Southampton to New York City. (More information to follow.)
On board we heard the misfortunes of some travelers who had spent time in London and were considering how to get to Southampton. They had too much luggage to take aboard the usual train to the port.
So they considered renting a car and driving down.
They came to the same conclusion and engaged an UberXL. The driver couldn't wait in front of the hotel, and in the confusion of schlepping all their bags to where he could park around the corner, two remained in the lobby. They were safe there but their absence wasn’t noticed until the unloading at the Southampton Holiday Inn. The two bags’ solitary taxi ride to join their companions cost £200.
However, by then it been realized that somehow the reservation was actually at a Holiday Inn in Northampton, which wasn't, as one might hope, just north of nearby Hampton.
And, with three ships totaling 8,000 passengers departing the next day, there were no vacancies at the Southampton Holiday Inn. I didn't hear if they were able to cancel the other reservation without penalty, but the hotel they finally were able to book was in a distant suburb, on the opposite side of the city from the port.
At least they didn't miss the boat!