I think you have made good choices, the Cotswolds and west to the Brecons.

I have always liked the areas going west into the borders. Forest of Dean (wild pigs), Wye Valley (canoeing), Brecons (wild horses), Usk Valley, Monmouth and Brecon Canal and north along Offa's Dyke and the Shropshire Hills. Opportunities for relaxing walking, cycling and on the water.

If you are in London, see the sights, but maybe a day in an outer borough to see a different side. In Richmond great views from the fabulous park back to the city (there's a binocular viewing point) and on Richmond Hill looking out at the Thames running from the south and west. Very nice walk or cycling along the Thames here, either to Teddington and further on to Hampton Court or the other way to Kew Gardens.