Hen Planning

I am planning a (last minute) hen party for my best friend. We were originally going abroad on a party weekend however the bride has since fallen pregnant and the wedding has been pulled forward to March. I was thinking of Valentines weekend, as a ‘Galentines’ theme. We are early 30s, there will be around 20 of us. We are all in London and the bride absolutely loves London, so ideally want to stay there but don’t have to be if there are better suggestions. Ideally I’d like to hire a room in a restaurant where I can decorate it valentines like, or is it better to hire an air bnb. Can anyone suggest anything? I’m open to anything and need to panic book soon. Thanks so much for your help!