I just did the same thing with my husband and went a few weeks ago to The Alexander House Hotel in Sussex. Only an hour from London, gorgeous hotel and spa and more reasonably priced than all the others I looked at. Would definitely recommend.

Bath spa?

Do you want countryside or urban? Birmingham has some great hotels with fab spa deals

Lucknam Park or Manor House in the Cotswolds. Both are quite expensive, but you may be able to find good deals, especially last minute.

umm, Limewood has been my favourite spa hotel matching your criteria. I think we went when it was a bit cheaper and had a Sunday deal. it is a beautiful spa with floor to ceiling windows over the forest and has a big outdoor jacuzzi surrounded by lavendar!

Pennyhill Park has quite good offers (especially on booking.com) it's a bit more corporate. It has an indoor and outdoor pool and lots of steam rooms in a moroccan style. I recall the restaurant being fine.

Stoke Park also has Sunday deals. The restaurant was excellent (better than Pennyhill), spa was not quite as big as Pennyhill. Stoke Park has nice grounds that border a memorial garden - it sounds odd but the memorial garden made for a good walk! Stoke Park is almost Slough, but not far from Windsor.

My husband just recommended Donnington Valley - he went there on a golf trip and thought the spa was good, this last hotel is prob the best value.

Enjoy!

My husband and I are hoping to book a weekend away at a Spa Hotel (in the UK) for 2 nights in July. (Without the kids!)

I'd love to hear some recommendations.

Ideally:

No more than 2 hrs drive/train from London
Not hideously expensive-eg we looked at Limewood and that's too much for us to spend
Has a Spa and indoor pool (Outdoor would be lovely too!)
A decent restaurant
Ideally within a short drive of an interesting town (but not essential)

Thanks!