I've had the same problem biking in the winter as well. I could easily keep my core warm with light layers, a windproof jacket and the heat generated in my torso and quads by moderately strenuous pedaling.

I believe the answer for cold hands is windchill and hand position.

My winter bicycling specific gloves had a patch on the thumb to wipe off glasses. The wind would blow right through that patch and freeze my thumbs first to the point of pain.

Since my hands were stuck in basically one position holding onto the handlebars, (that allowed quick access to the gears and brakes), there was not much I could do. I tried other gloves I owned but they were worse with the wind.

A quick look at windchill numbers helps show the temperature difference:
http://www.nws.noaa.gov/om/cold/wind_chill.shtml

For my feet, I found the problem was more that my clipless pedals conducted heat away from my feet. My soles would feel it first at the connection point between shoe and pedal. I could not fit too thick a sock inside my bicycling shoes.

For what to do to keep warm? I would say trying out different gloves and using toe warmers can help. If your friend can find gloves with liners, (that still allow access to the controls), he can slip toe warmers between the layers.

Two things I never tried were over booties and changing out the insoles.