Giveaway expiration time

There is no hard rule on when you can resub. I would give him 1 week to respond and then resub. Make sure when you resub to resend the gift to an email you own, so you dont end up with no gift for second giveaway.

I would say one week, just like the gifter has 1 week from when it closes to send it out. If after one week from the close of your giveaway the person doesn't redeem the gift, send them an email telling them you are going to pick a new winner.