Does seem to depend on where you are.
GB3BF - Bedford, BEDS is pretty dead and not sure if they still have the evening club net. (2m)
GB3OV - St. Neots, CAMBS is still pretty active with regular nets. (70cm)
GB3PI - Royston, CAMBS always has some activity or someone monitoring. (2m)
GB3TU - Tring, HERTS used to be fairly busy. (70cm)
GB7CT - Tring, HERTS always used to be busy too. (2m DMR)
Can only hear GB3VA Brill on a morning lift and I remember it used to be fairly busy so not sure what's happening there.
I would have thought MK and surrounding areas would have activity due to the club.
Not been using the repeaters myself since disappearing down the FT8 rabbit-hole over the last two or three months. (Embarrassed to say really.
)
Always worth giving a shout on them if you're a licensed Ham just in case.