Doing IR colour sep will be easy. The interesting wrinkle is what colour channel you dump the IR info into; IR is, of course, invisible to us and doesn't have a colour. So it is a matter of choice. For spy photos you'd probably want the IR to be something other than red so that it stands out from that adjacent colour. But for more pleasing images I suspect that putting the IR image into the red or deep red channel of the final image will work. People can simply try and see for themselves... many creative possibilities here.
Of course, the individual b&w images could also be developed as positives, they don't have to be developed as negs.
Smart chemists like Ron could tell us how to make IR autochromes.
As certain film options go off the market, we'll simply rediscover all the ingenious things that people used to do. It'll be fun, it really will.