I love the suggestion about the thermostat. Go through your horse work clothes and separate the very grubbiest and holiest for wintertime mucking. I have 7 degrees of clothing from the very nicest (Holiday singing & fancy parties/weddings) to the stuff I wear to muck out after the chickens.
I have winter clothes that I wear in side to do what I'm doing now, and winter clothes that never go outside in the winter, but I use for house cleaning. You stay warm by wearing layers to put on and take off when necessary. Get your SOCKS together. We sweat in our socks with any kind of heat, so you should change your socks many times a day during the winter. The worst thing to happen to you is to get sick, so this will keep you warm and healthy, as well as a very cool and healthier house.
Instead of putting sweaty, but not really dirty socks or layers in the dryer, find a place to hang them to dry. During the whole year, I hang my outdoor chore socks on the water pipes by the back door in the basement to dry until I need them again. Even with this year's humidity my dehumidifier dries them overnight. I also hang my damp sneakers on the hand holds that the previous owner put on the wall down the 5 1/2 basement steps. Actually I wear sneakers to feed my animals with through almost the whole year. I get them used and cheap and I totally wear them out. Right now I am rotating between 3 pairs. I don't throw them away until they either split or the sole cracks.
Use or buy the cheapest sweatpants for winter feeding. You can put a pair of long underwear pants AND another pair of pants underneath them, if necessary.
When you layer, go north, then south, etc. That is, your tuck your bottom shirt layer into your pants, the pants go over the next shirt layers goes over, then the pants go under. Layering correctly doesn't allow for any gaps that allow drafts.
If you have Cartharts, save the jacket and overalls for feeding in the the coldest weather.
Start checking your windows NOW. It isn't too early to fill cracks and put some caulking around them. I have three windows that need to be fixed before the end of next month. Spend the money to check our your furnace right now. A repair in the middle of the winter is pricey and if you have to wait too long and it's very cold, you will also be paying for pipes that have burst.
Assemble and wash and dry your warmest blankets. Strip down and change completely for bed. Use the lightest and warmest blankets. Down comforters are the very warmest, then wool, then cotton. Hats also keep your warmer than none.
If you are a coffee drinker, consider using your coffeemaker for a runthrough, instead of making more. You may think I'm daft, but I'm beYOND frugel and downright cheap! Stick deodorants will last for months and months if you don't throw them away until you've used every little bit. I keep the almost-gones in my dresser drawer and use a q-tip to push the pieces out. I use that on Saturday when I just having shopping to do. I also cut open toothpaste tubes and use every last bit.
I buy practically everything for myself and for my business on clearance or on super sale. In the USA, grocery stores and others realize that the first full week of month is when most people are paid, so they are flush with money. They wait until the last two weeks to really put things on sale bc most people don't have the money to buy, then. Also, if you are really frugel for Christmas, you can buy in January when most people don't spend bc they are heavy in Christmas debt.
LEARN TO SEW
Many people leave things unworn just bc they have lost a button, or a hem needs repair. Just go online and you can learn how to properly sew on a button and how to do a tailer stitch. Also, repeair your play socks, instead of throwing them away. Use your grain bags in the barn for garbage bags INSTEAD of plastic bags and save a bundle.