I have stalled in a few spots on the work at hand but I am still composing preludes and fugues for solo guitar. I certainly won't manage to finish all 24 in less than a few years but I do believe I should be able to get to the halfway point before this year is out. It took Rekhin five years to compose his set so I won't be surprised if it takes me five years to complete mine. It took roughly ten years to finish the four duo sonatas in the cycle for guitar and woodwinds and those are considerably larger works.
Yet it also bears repeating that fugues are among the most complex musical works to write and the guitar is an exceptionally unforgiving instrument for contrapuntal music. Chris Kachian is correct to observe that sustained three-voice counterpoint is impossible on the guitar (composers who are not guitarists should go pick up his Composer's desktop guide to the guitar) There is no trouble, however, with sustained two-part textures that convey the effect of multiple textures.
This two parts in place of three or more brings with it other challenges.Even in works like Bach's fugues for violin stripping everything down to a single line punctuated by chords means you have not sacrificed the implication of thematic development throughout your piece. But I don't feel like getting into all the details of that now.