Good news. Yesterday's measurement of my route was wrong by 100 paces.
It is in fact a full mile plus maybe 15 meters.
So the times that seemed fast were in fact fast and not some measuring error.
Caveat: fast for running on ice and snow in winter.
4 miles today, about 9 flat pace.
That puts me about 12 weeks ahead of last year.
If everything holds together I might consider a marathon in the fall