I haven't been to Northlands, so I can't speak to that. That lineup looks sweet!!! However, some important considerations to festival taping are as follows (not an exhaustive list).
Excellent guide Chris. A couple of comments to add...
Get big beefy screens or furs for festival taping because they act as shock absorbers and/or mud flaps if your stand ever takes a tumble, which can happen. I've come back to my mics after a storm thinking I'd secured everything great before leaving the bowl or whatever only to find the mics capsule face down in 5 inches of mud.
Second the suggestion about batteries. I would strongly suggest overdoing your battery planning. Take WAY more capacity than you expect. I'm real close to my 100th festival and I can tell you 100% that batteries are the one thing that used to kill my festival taping experience more than anything. That's a thing of the past for me now bc I have something like 25 tekkeons and my cables and/or recorders are such that I can hot-swap batteries, so I never have to worry about losing power as long as I keep an eye on my battery usage during the day (which sometimes gets away from me depending on beer consumption).
An alternative to weights for your stand are stakes.
Alot of guys like to be FOB during fests, but I find that too much of a hassle of managing my stand and blocking drunk people. For maximum festy enjoyment, get there before crowds amass and set up with your back to the barricade in front of the board. I set my stand up than park my camp chair right next to it. I usually will be recording from first act till late night, so that's sometimes 16 hours of recording, so the camp chair is essential to my festival enjoyment. I'll usually pick either corner left or corner right, because alot of FOB engineers don't like the stands directly in their sight lines.
If it starts to rain, put a towel on top of your umbrella. That'll keep the pitter patter of rain drops from your recordings.
For what it's worth, 24/48 uses about a gigabyte an hour. So a 128gb card will be plenty for a weekend, and 64 usually is plenty but it can get pretty full if you do a four day festival.
I always take my laptop and download yesterday's performances as a safety in case something ever might go wrong with a card, say the last hour of the last day of a festival. If I don't have my laptop, I change cards each day for the same reason. I've never lost an entire festival, but always have lived in fear of it happening.
$10 wal mart ponchos have always been my go-to for rain-gear. Small and fits in my bag with little or no space taken up.
Since this is your first festival be aware that 75% of festivals before about July are mud pits by the last day. Gallosh type footwear or waterproof hiking boots end up saving your health.
If you like to imbibe, many festivals have police and animals outside the gate and upstream of the festival entrances. Plan accordingly. I've heard that spending a night or two in jail can ruin a festival experience.
Regarding the suggestion about string light on your stand...that's a good suggestion, but once the sun sets I just keep my led flashlight in my hand and when someone gets close and just shine the light on the ground to help guide them around my shit or to keep them from tripping on a stand leg.
Friends make the best blockers ever, so if you're going with others, make it a team sport.
Take a penknife or something discreet with you to kill beach balls and other inflatables. All you have to do is put a pinhole in it and then knock it away and chuckle while it slowly deflates. Nobody knows you're the murderer.
If I think of anything else, I'll amend.
Enjoy the festival!