Yes, I would say having a regular tipple will make your journey that bit ore pleasant, though I'd recommend some soft drinks in between to counter headaches. Peeing is not an issue, they have plenty of dubs, and the occasional walk to the dubs and back you'll find means suddenly when you get back to your seat you are much more comfortable, for that little bit of movement and exercise.

But back to my list - only wished i'd followed this advice once, but wish I had-

4. Your choice of HEADACHE pills. Aspirin, paracetamol, whatever. They aren't allowed to give you anything on the plane and if your head chooses those hours to ache (and I think the changes in pressure, the noise etc do tend to cause headaches) you'll wish you had a couple of pills to pop. My personal choice is Nurofen.