The UK is going to become stronger over time because of this, they should be happy to be free of the EUSSR
I'm actually not sure what will happen. It is going to come down to how well the UK government handles it, if the even let the referendum stand (it is non binding and they are already calling for a revote. the UK government is very liberal, even by our standards. I wouldn't be surprised if they even try to punish the people who supported this by doing things like freezing trade deals, etc.
It could go smoothly and be transparent, having a relationship with the EU similar to Switzerland, or it could be a disaster.