Either in London or easy reach of South East London.
I'm having a look now and going round in circles. I'd ideally like somewhere with a pool, sauna, steam etc and some treatments with a nice lunch or afternoon tea but that isn't heinously expensive.
So that discounts your Champneys/ Grayshott/ Pennyhill Park places as they are a bit too pricey. I liked the look of both Sopwell House and Nutfield Priory (both have packages for around £70 a head including some food) but they both have some pretty poor reviews recently.
I've also looked at the SpaLondon places but am put off by them being run by Better - can anyone actually recommend one (again, varying reviews).