Here are some things to think about:
Transposing up:
- fretted notes are not a problem unless you run out of fretboard at the dusty end, but open strings will need a fretted alternative.
- some things just sound wrong played too high, so you may want to think about taking sections down an octave.
Transposing down
- eventually you will come to the nut, and have to play the note on the next lowest string.
- if the new lowest notes are lower than the pitch of your lowest string, you may have to take sections up an octave.
The results of transposing may leave you with a piece that's easier to play, or much harder. Personally I rarely think in terms of just moving the position, but then I tend to work from my own transcriptions in music notation, and address a transposed piece with fresh eyes and ears,