If you do stop in Patzcuaro, El Pozo is still open and running. However, the north bypass for Morelia is a real mess. Serious mess, add an hour to the normal 25 minutes around the city, and the conditions seriously sucked. This is as of 4.5 weeks ago from friends. We did it in late October and didn't know if we'd make it through the construction.
Personally? The short road from Morelia to Patzcuaro isn't usually one of the areas that get hit. I wouldn't pass on Patzcuaro, and it's a great way to break up the drive.