Oftentimes indoor cats have problems with inappropriate urination on couches, mattresses, and carpets during the winter because their normal patterns are interrupted, and they can even become bored.
One thing you can do is to keep your cats entertained, which just means to be social with them and playful and provide them with stimulating environment.
Everyone knows that cats love strings, so even an old pair of shoelaces can be great entertainment for your cats to help them stop urinating on your carpets, if you just pin it up somewhere where it dangles, or if you play with them by hand.
You can even make dinner time fun by playing games with their food. Some cats, like Lucy the black cat pictured here, love to play fetch. Throwing a few food bobbles or crunchies or treats around to allow them to fetch it can be great fun for your cat, and at least distract them from the idea of peeing on your carpet!