I think using the DNS provider (Cloudflare) that you mention is okay and can open the block from the ISP. I think that does not break the casino rules, but you should ask them.
If forbidden they must add it to specific rules. this thread is useful to open all casino eyes if the user can open blocked not only using VPN, in the next we can see the rules forbidden using VPN and change DNS.
Can this works in another country? And if really it works I will not advise anyone to invest in it, because a banned sit is liable to stop working at any time. If the site is working for like 3 to 5 month interval and suddenly the site stop working and by then you invested money in it..at that point it would be heartbroken.
I know that for one to become a successful person in the society, he or she must have risked one thing or the other..but successful people took calculated risk not careless risk.
then, you must be carefull to use it and don't make you comfortable.