I expect the first event of S7 will take place in the last few days of May / start June.
That"s a terrible weekend for poker. There is a sweltering heatwave predicted and traffic is also expected to be awful. There may be a royal event too.
The weekend of 25/26 May is a much better option for you.
8/9 June also seems to be good.
Anyway, you"ll have to change it on account of all your players being at the Portsmouth GUKPT.