I have travelled on Queen Mary a couple of times as a solo and found it great. they have meetings for solo travellers, and dance hosts if you like to dance. I get the best deals from Planet Cruise or from Imagine cruising, but it’s best to book early. Good luck!
I have a yen to go on the Queen Mary as a solo passenger, dread to think what it might cost though. Before, when I have booked cruises I have looked at their site, put in my preferences, then the choice and prices were shown. However now it’s impossible to do, they appear to have stopped on line booking, but why?