I abandoned the idea of having a jacket for different seasons.... can't pack it all.... plus wanted hi-viz... now use an Olympia Airglide and layer up for the anticipated weather. For extreme cold, long sleeve Minus 33 brand merino wool underwear (thin, light, moisture wicking), Warm & Safe heated jacket liner (breathes, and has heated collar and outlets for pants and gloves), Olympia quilted waterproof liner to block wind, and Heat Troller mostly set on low. This thing can cook you if you want it to.
On the bottom, Olympia Airglide pants, liners in for the cold and Minus 33 longjohns, merino wool socks, Y-harness down the legs to Gerbings heated insoles... on same controller as jacket liner, although one might want those a bit warmer, can add another controller with a Y-connector if desired or try it with the glove controller in a deep freeze, but it might be too hot if on high. OK if you keep the balls of your feet on the pegs so they're up out of the cold. Gloves are Warm & Safe Ultimates hooked via the jacket liner input for a separate controller, mostly on full high. Gerbings G3 gloves not recommended, do not have breathable liners. G5's probably better.
If it gets hot, just strip down layers. For anything over 65-70F, ditch the Minus 33 top and wear a tee shirt with Minus 33 merino wool boxers. The idea is you can carry all this stuff without exceeding your luggage capacity and be prepared for all weather. I also have a FrogToggs rain suit which breathes but will block wind/water.
Windshield Rifle +4+5 and Baker Air Wings will take care of most foul weather, perhaps I'll add some removable homemade air deflectors to my dash shelf...... and yes heated grips are a staple.
Bottom line, I can ride until it's dangerous with frost and ice.... be aware of that before you get too comfy and overconfident.