Okay, I don't know for SURE if this would work (obviously, someone with experience can give a more educated and certain answer) but since we are both doing a longhorn pattern I'll put in what I was THINKING of doing. I was going to try and do the intarsia thing. I THINK that with the exception of a few areas (that I'll have to tinker with) that I can work it so that there aren't lots of yarns on the backside. (I'm doing a discloth so don't want all that mess either). Since I will HOPEFULLY reach this point in my pattern before you do, I will be sure to let you know if it is working or bombing.
Of course, should I see someone's suggestion that actually works (tried and true versus my let's see what happens attitude) then I will go that way.
Best of luck in your knitting endeavor.