To clarify a few points, I drove to the place where I usually park, saw the blocked off spaces (about ten on each side of the street), did a semi-legal k-turn, parked and hurried into the church, all in the space of a minute or so. It wasn't until I thought of the situation later that I realized how far away some people would have to park. If I had, I would have left the space empty and parked farther away, but I was really just focused on getting myself into church.
I don't think parents park on the street to avoid the drop-off line. In four years of attending weekday Masses, I've only seen one parent walking his child to school, and it's fairly clear that they live nearby and walk from home.
Attending Mass at another parish wasn't really an option since there are no Masses later than 8:00 a.m., and it was already just a few minutes before 8:00.
Offering to park others' cars would not work for a variety of reasons, insurance liability and the time factor being only two of them.
I'm of an age where I read the obituaries every day (mainly to be sure I'm not in them), so I know there were no larger funerals scheduled for that day.
I think that the thing that I found the oddest was that there was not one car parked in any of the blocked-off spaces after Mass, nor were there more than a few spots taken in their lot. They could easily have put the signs out after Mass.
I do wonder how the business owners whose spaces they were blocking feel about the situation.
Thank you for the responses.