OK, it's been mentally challenging, but I took off enough time to let my left heel quiet down. Two days ago I easy jogged two miles, the same today. My plan is every other day running for the forseeable future. In June, that means running on odd days. On other days or in the evening I can ride my bike, having finally fixed a flat from last year. New tube, no less!
It's hard to predict when I'll be able to ramp up the miles. Not earlier than July, it looks like.