Hmmm. This is a really good question. It is one I tend to ask in March or April, when I am SO DONE with winter and winter is nowhere near done with me.
A few of my past solutions echo comments made above:
A new top/ knit in a colour that speaks of the new season more than the old. (Burnt orange would be brilliant here for you; in my own case, I have a pale blue cashmere sweater that in colour speaks "spring" to me while in weight it still is winter.)
If the weather is dry I also try to wear flares, or else lighter coloured bottoms which I avoid all winter due to the risk of slush stains. I'm not sure what the equivalent might be for you. Maybe a new pair of jeans in a different colour and/or a patterned pant?
Switch out the footwear. As soon as it gets warm and dry enough for me to wear booties vs. snowboots I look for light or bright coloured footwear as a switch up from the old. In your case, you might start wearing lightweight booties part of the day?
Accessories. Splurge on a great new bag or belt or necklace...perhaps a statement item? Or just go cheap and cheerful with a fun lightweight scarf in a new-to-you colour, or a cuff?
Hat update? You wear your fedora so well. Maybe another style?
New hair cut/ colour? Or new lipstick?
Lots of sympathy from me. There is nothing I loathe more than the long dragged out season when everyone else seems to be changing seasons.