I have no idea.

CloudFlare doesn't offer VPS instances. Google and Amazon are in a league of their own and, last I checked, don't offer the similar services at the same prices with the same level of support and same controls. Amazon might send you a nice bill at the end of the attack depending on what type it was.

DigitalOcean, as an example, routinely receives DDoS attacks and will just nullroute your VPS automatically until the attack ends.