Yes, I often leave my games running on 1/2 speed, and sometimes longer than overnight. Keeping a Farmer is important! Sometimes I've come back to an empty food bin.

When I first started playing, I would use 2x speed when watching the game and switch when being away, but now I'll usually keep the game in 1/2 speed all the time. It takes "real time" longer for nursing babies and the crops, but I've found that the villagers seem to get so much more accomplished at the Research Table for the same "village time."