I use the TourMaster Synergy heated vest with collar, no other heated gear. Per their website, it takes 51.6 watts and 4.3 Amps.
My grips are Warm-n-Safe with an in-dash variable controller.
It all works out to be sufficient heat for down to freezing temps, with First Gear jacket and pants, liners
13 KTM500 XC-W Holy f'ing sh*t!
05.5 KTM950 Adv(S) in the rare all orange color
10 Yammie FJR 1300 10 Wing