I don't think that's a good idea and here's why.
If your fingers or feet get cold, that's caused by your body having too little insulation. Your body is removing heat from non-essential parts to keep you alive. The solution is to insulate your entire body with enough clothes.
Now, when riding a motorcycle your body produces probably around 100 watts of waste heat (idle heat). When riding a bicycle, you additionally are producing 100 watts of mechanical power which creates along with it at 25% efficiency 300 watts of waste heat, so you have 400 watts of heat total.
The problem is, you probably need at least 2 hours of runtime to have acceptable range, which means for motorcycling to match the heat power output of your body you need 200 watt-hours and for bicycling 800 watt-hours. This matching of human power output is for cases where your clothing has half the amount of needed insulation.
Do you know how much 200 watt-hours weigh? Even with lithium ion, that's a lot. My ebike battery (500 Wh) weighs 2.9 kg, so you need at least 1.2 kg for the battery. And that's when the battery is new. Ideally batteries should be usable when they have 70% of capacity left, so using that measurement, you would need 1.7 kg for the battery.
For bicycling, that would be 4 times more ridiculous (6.6 kg for the battery).
My opinion is that the best approach is to insulate your entire body well. And just in case you have too little insulation in your body, causing heat to be drawn out from fingers and feet, you should have lots of insulation on those fingers and feet that would not be necessary normally but could be useful if for example due to you becoming tired your heat output decreases.
I think that in most cases, it would weigh less to have more insulation rather than to carry a heavy battery and electric resistance heaters. It would cost far less too.
However, if you tap into the electric power output of a motorcycle, then it might make sense. I have a heated steering wheel in my car, and that's useful because it doesn't need a big battery. It just uses the alternator output.