I am worried that the one in an hour will also crash because they will get close to the same volume unless they limit you to register to only one of these.
Yes, since they haven't blocked registering for both, you could win 2 tickets. The first one will auto-register you for the tournament and the second one would drop into your available tickets. I've won a ticket before, then couldn't play on Sunday, then one another ticket before using the first one.