Not quite done. 5. Kg7 Kf5. What next?
What is your favorite endgame position

I’m done
You shouldn't quit after finding White's first five "only" moves. Just a couple more to go.

c4 for which side when?
6White
5. Kg7 Kf5 6. c4 draws.

c4 for which side when?
6White
5. Kg7 Kf5 6. c4 draws.
and what next move draws?
That's correct. {Trexler's diagram has the pawns on the wrong files.)