Here's my hot weather strategy: repackage the wine and evacuate every bit of air when closing. Stow it inside a ziplock inside some clothing next to my water bladder, which is filled 3/4 with ice. Then, plan on drinking it on night 1 (which makes you VERY popular if hiking with partners). I often include some sort of meat dish on night 1, packing it frozen next to the wine.

The spirits support nights 2 through...however long you can string it out.