Holiday parks/cheap self catering South East uk

[twolittleboysonetiredmum]

Hi
I'm trying to find cheap/reasonably priced self catering accommodation either in Berkshire/Oxfordshire/bath area. We need to visit family in those areas regularly with our 3 small children. Can anyone recommend somewhere? Thinking caravans/lodges as they're probably cheaper and have parking etc. I've looked online but am struggling!