Boosting heat output in 05-06 Triumph factory grips

You guys (and gals) who live in California, Arizona, and the Deep South may be satisfied with your 05-06 Sprint factory heated grips.

But for those of us in the northern, midwest, or east coast states, or our British/Scottish/Irish brethren, the grips just don't put out enough heat when temps drop below 50 Fahrenheit or so. At 58 degrees north latitude in Juneau, Alaska, I may have the farthest north Sprint in North America, so I am particularly interested in hot grips! Even riding from Missoula, Montana to Spokane, Washington on this past September 1, the temps. over the passes were in the low 40s and my hands were cold with the grips on high.

I was told by a guy who owned both an 05 and an earlier Sprint that Triumph received complaints that the pre-05 factory grips were just too hot, and the high setting was practically unusable. So, Triumph cut back the heat output, but way too much, in my opinion. On my bike, the heat output on low is barely noticeable, and high seems about what low should be.

So, the question is, how can we Sprint riders in colder climates boost the heat output in our grips? A related question is how did Triumph cut the heat output from the pre-05 grips to the 05-06 version? Either the grips have less wiring, or Triumph put in a different resistor in the switch to reduce the amperage going to the grips.

In the latter case, all we would have to do is replace the switch with either a pre-05 version, or since that version may be too hot, replace the resistor with higher amperage version, or replace the switch with a rotary dial like a Heatroller used on heated jackets.

Anybody out there with electrical knowledge with advice on this issue? Or someone with a multimeter and access to both an 05-06 Sprint and a pre-05 Sprint with factory grips who can check the amperage going to the grips?

Thanks,
Jack