It seems that IG at least are expecting many to just switch to somewhere outside of the stupid new regulation area and even sent me an email regarding this with a link to this page where you can get more info and compare the different countries products:

https://www.ig.com/uk/compare-our-leveraged-trading?CHID=3&QPID=22380&tid=afa72f2fd4a438abe9c0f09f713fa6bf

For me the only possible downside would be the tax implications of not using tax free UK spread betting and the fact that as a new account they will probably put us straight on to limited risk accounts which in my mind are useless for serious trading.