We have not had any luck. I have also explored hiring a driver and car for a half-day, but have not had any luck with that either. If you do find an option for private exploration, please post as I am still looking!
Hello. I can provide my recent experience that as an American boarding the QM2 in Southampton, I did not need to provide proof of travel insurance. I had the same question/concern and our travel agent advised that the requirement did not apply to US Citizens. Enjoy your cruise!