Yeah I was iffy about getting it too, but I was able to barely squeeze it with 29 hours and 45 minutes...
I didn't freeroam much but I did complete both Brucie's car exports and Jacob's drug smuggling side missions on the way.
I took a cab to a lot of the last missions, and skipped some of the cutscenes near the end (REALLY stupid on my part) because I was afraid I wouldn't get it....