1.3 amps is 16 watts, no big deal. Switch every bulb except headlight to LEDs and pretty mmuch make up the difference.
EDIT: I was just reading up on the Oxford grip heaters and they draw 18 watts EACH, or 36 watts total. That is significant. Go by the local electronics store and pick up a 50 watt resistor to lower the draw. The folks at the store can measure the resistance of the heaters and provide a suitable resistor. Generally, grip heaters are twice as hot as they need to be so reducing current by 50% might be a good place to start.