Only works if they have DDos protection, Another IP you can switch to once attached and you have no services you need people to connection to. You can't hide your IP if you need someone to be able to connect to something like a website.
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.
DDoS protection does not really exist, you can get firewalls that will stop the packets going any further than there, but the firewalls still need more capacity than the attack in order to not fall over themselves, and those firewalls are usually reactive and not always running due to their triggering on false positives.
So as has always been the case, the only protection against a DDoS attack is to have more capacity than the attacker.