I've used both electric vests and electric jacket liners for many years ato extend my riding season here in MN.
The Gerbing line has been my choice compared to the Widder brand and others. I prefer their jacket liner (about $200). It comes with a switch control, but I've gone to a Heat-Troller electronic thermostat for more control.
The jacket liner consumes 70 watts on high, less on lower settings. Most modern bikes can handle that without strain. Still, a voltmeter can show if you're discharging the battery.
The jacket liner has heated sleeves AND a heated collar. I put the collar under the helmet strap for a cozy neck and chin as well as warm body and arms.
Try <
www.gerbing.com> for more information on their products.