It's hell.
Never parked in a "public" lot so I can't say. Used to have a pass for years until they dozed my lot and I didn't have enough points. I imagine the public lots fill up way earlier than you plan on getting there and only imagine getting out is worse.
This is based on about 8 years of trial and error and it's about a mile and a half walk:
We park in the neighborhood NE of LSU Ave: Cornell, Oxford, Harvard (
https://www.google.com/maps/place/L...2!3m1!1s0x8626a6e6dea23675:0x8b4f216d204e4766) where we can find a spot. People put out cones and crap but we can usually find a spot 1 1/2 to 2 hours before kickoff. We sometimes arrive later than that. It's a very nice neighborhood so cars are never messed with.
So, get off at Acadian go straight through Perkins and Acadian changes to Stanford. Keep going straight into the neighborhood once you past the lake on your right. You'll see people turning right on to W Lakeshore. Don't be those people. They have parking passes. Then take your second or third right on Harvard or Emory, depending on traffic, and just find a spot. The further SW you park, the closer you are to Highland. The further NE you park, the closer you are to W Lakeshore.
I recommend walking down Highland, sidewalk all the way and will take you basically straight to Tiger Stadium. Walking down W. Lakeshore can be more direct if you park further northeast in the neighborhood but you've got about a one foot wide path to walk on the stretch along college lake. If you've got little kids, you'll fear for their life for about two minutes. Also, if you're a wuss and irrationally fear for your life based on the stories told here, your walk to the car via Highland after the game goes though the least tail gait-ed area of campus. Finally, if your seats are in the visitor section, then parking on this side of campus brings you to the south endzone where the visitor gates are.
If it's a day game, parking won't be too bad. If it's a night game, it will be hell.