Dave, I hear ya. I've never been a shower guy, but I love a long soak in a tub. I've considered buying or making a Japanese style sitting tub (they have a 'car-door' on the side) and use much less water than a European style bath.
For now, I suffer, and take a shower about twice a week, or when I feel dirty... what ever comes first.
Things that help:
heated flooring... living in the Yukon, I have the opposite for 7 months of the year.
natural light... ditto
short luke warm showers... somehow the less temperature swing the better
a bucket in the stall... sometimes I wash only my hair over the bucket, the rest of me stays dry and therefore warm. The bucket is then used to flush the toilet or water house plants.
Cat baths... use a warm cloth to wash areas that need it
failing all that you could build a wood fired rocket hot tub!