Don't buy it via VPN, it's a tax fraud.
Also, using VPN to download your game early is likely against the TOS and if you plan on breaking it, at least only play the SP, completely offline.
Your product key contains regional information, when you log in to the game, your product key is sent to the EA servers. EA can easily ban every single EU key that's connecting before 28th if they so decide, and there's nothing you can do about it.
Even downloading the game is probably very risky and playing SP could easily store information on your computer, which can be then used to ban you when you connect, even after the game has been officially launched.