Based on our experience at the Molitor jersey night last month, I recommend arriving as early as you can. On jersey night, the home plate lines stretched out to Helfaer Field at 5:40, when the gates opened. I saw that via others' social media posts, because we were still headed to the park at that time. We got to Blue Mound/Hawley at 5:55 - which was right in line with our normal arrival time of about an hour before first pitch - but barely moved for the next 20 minutes, landing a spot in the Molitor lot (irony noted) at 6:15. The lines at home plate moved relatively quickly, but were still long to get in. We finally reached a gate at 6:25, and not only were the jerseys all gone, but so was all evidence of a giveaway (boxes broken down and removed). I realize that the backpack is only for ages 21+ and the game is on a weeknight, but there are only 10,000 packs and I think that (plus the extra visitor traffic a Twins game would normally bring) might outweigh the other factors. If you can't be super early, I'd recommend trying a non-home plate entrance, which might have less of a wait (though might also have less giveaway items). I wouldn't bet the farm on still getting a pack at 6:30. Hope that helps.