Never done this before but very tempted as I will be out for this weekend. So won't get to unpack the game till Monday. Is this a very bannable offense under steam?
Strictly speaking, using a VPN at all is against the SSA, but in practice Valve only cares if you're using one to aid in cross-region purchasing or the activation of region-locked gifts. Nobody has ever been banned or had their account restricted for using one solely to unlock a game early or activate a region-locked key.