Their fries are the worst fries I've ever had anywhere ever
I love their fries, but they do take some babying to get right.
Many order them "well done", and that seems to suit them. I used to do that, but I don't anymore.
The game with In-n-Out fries is to not let the steam destroy them.
If you're eating in the restaurant, they put the burgers and fries in to a tray and then they put napkins over the fries. Yank those suckers off immediately.
Once back at the table, dump the fries out of their trays and scatter them, letting the steam ebb off as quickly as possible.
If you get them to go, you can do the same thing. I tell them to serve my food in a box, and you can scatter the fries the same way. Mind, if you them put them on the front seat in the blast of your air conditioner, you will likely be unhappy. DAMHIK. But, as a general rule, In-n-Out doesn't travel well. I think everything they have is much better fresh in the store.
If you put the fries in a bag, and seal it up, yea, they're toast. Actually, they're no toast, that's the problem. They're a steamed soggy mess.
I love In-n-Out. Nobody grills onions the way they do, and I think their fries are worth the effort.
The Habit does similar horrors to their fries. They put the burgers in the bottom of the bag, stack the fries on stop, and then shove a heap of napkins like a stopper on top of it all. Disaster. I actually strived to train the window person at my local Habit to try and not do that, tried to come up with magic words and the right order so they would understand to avoid that problem, but it never worked. So, I just have to pull over after the window, and tear everything apart and reassemble it in the car.
Chic-Fil-A cross cut fries travel pretty well. Red Robin has these potato, thick crinkle cut chip like fries, Yukon Potatoes I think, they travel really well, but RR uses vented serving trays, which also helps.