Hi,
If you have a successful business in London I would not give that up to move to Chengdu. The cost of living in Chengdu is a fraction of what it is in London so I don’t think you’ll have any issue making a reasonable living here. But as any foreigner who has started or managed their own business here will tell you, it is not easy and comes with a significant learning curve. Speaking Chinese and having a Chinese spouse will be huge advantages. Just my $0.02, good luck!