Freezing your drinking water during wilderness travel can become a real issue for those not used to working or hiking in temperatures below freezing (32F). In single-digit temps, your drinking water can freeze in just a few minutes if not protected in an insulated wrap of some sort.
Water filters, such as the Grayl, Sawyer, and LifeStraw also freeze up quickly which not only voids the warranty, but degrades the rubber seals and destroys the filter media inside them. Any filtration devices carried in the winter months much be kept next to the body to be kept warm, which can be problematic.
Additionally, in below zero temperatures, locally sourced water freezes up, which means you may have to chop through thick ice to access whatever water may still be available. This process is potentially dangerous and physically taxing, which burns up precious calories which will cause you to need to eat more to maintain your core temperature.
So, here are some helpful tips to help you keep your drinking water usable at all times this winter:
Do not bury your bottle in your backpack or haversack. Stowed this way allows it to become too cold as your pack contents often do not provide enough warming insulation. Also, you will be less likely to drink from it as often as you should.
Place a stick or plastic spork inside your bottle. Doing this will increase movement in the bottle as you travel, which will help prevent ice from developing too fast.
Carry an Insulated bottle. You can insulate your single wall bottle with wool socks, reflectix insulation, or by placing hand warmers around the bottle during extended travel periods, and it will all slow the cooling process. Also, consider carrying hot water, which will cool down slowly as you travel, or just use a double-walled insulated container such as a YETI, RTIC or Ozark Trail specifically designed for keeping hot things hot and cold things cold. They work great for hiking and woodland travel. Just realize that you cannot boil water in them.
Drink on a schedule. Cold and wet weather trick your body into a false sense of hydration due to ambient liquid in the air and environment. You need to drink more frequently when it's cold as you're just as likely to suffer from dehydration in the middle of winter as you are in the heat of summer.