OK, everyone's experience will be different, but I've made dozens of beeswax-lined tankards, mugs, tumblers, cups, etc.... over the past several years and never had an issue with the beeswax degrading due to the alcohol content of the liquid.
I've used them for booze on the rocks, neat booze, booze cocktails, beer, milk, iced-tea, and even wine. In my un-scientific experience, full-proof liquor is not a problem for pure beeswax. I still use a 6-year old mug quite regularly. Damage and ruin to the beeswax has only ever happened because of physical trauma, like dropping.
Although I've never used it, I've always assumed that brewer's pitch was better than beeswax in terms of the physical strength properties (resistant to dropping). I would never have assumed that something called brewer's pitch would be less able to withstand alcohol than good-old beeswax. Is this really true?
Very hot liquid is another matter, I once did an experiment with hot coffee in one of my beeswax cups and it was not pretty. Although my test was not scientific in any way, I did confirm my theory that 'hot' liquid can ruin the beeswax (duh).
Be aware that some of the 'food-safe' epoxies might not be recommended for constant contact with a liquid as would be needed in a cup or canteen. For example, I experimented with a product called Envirotex Lite, which the vendor says is safe for food 'contact' (i.e. cutting board) but not for immersion (i.e. cup or bowl). I made a few shot-glasses and a tumbler with it just to get the experience of using an epoxy, but compared to beeswax it was very difficult to work with and if it were my only option I would have given up on making drinking vessels due to how hard it was to get a good finished product.
As soon as I get my workshop back in order I'll try making a canteen/bottle.