is this something we should do?
I've never heard anything specifically about Gate 13, but I've shown up early a few times and I'll be happy to share a few of my personal pointers...
(most importantly) Don't stress over anything. Just relax. The morning lines to get in will probably be longer than you expected. It's ok. Your line might not move as fast as you think it should. That's ok too. The line two lines over from your might open up an additional turnstile and everyone in that line suddenly moves up 20 feet. That's just fine.
Seriously, don't stress. This is supposed to be fun and relaxing. You'll all make it in eventually, and out of the 12 or 13 hours that DL is going to be open that day, an extra 10 minutes is no big deal.
Some lines feed into one turnstile area, and other lines seem to feed into two. Some turnstile areas have both turnstiles working, and sometimes there are those that only have one. If you're really worried about which line is shortest and/or going the fastest, then take 60 seconds and scout out all the lines before you actually jump into one.
I see lots of people break their party up into two lines, and right at the end the half in the slower line rejoins the faster half. But each time I've seen this done (or done it myself) I wonder if saving those extra 2 minutes was really worth it.
Strike up a friendly conversation with the people around you. Sometimes I'm enjoying the chat so much, I seriously don't even notice the time at all.
And remember that DL holds a *lot* of people. It'll seem crazy-crowded while you're in the line to get in. But once you've actually made it past the gate and worked your way back into the park, it'll be nice and un-crowded (for the first few hours anyway).