Well, kakku's tip worked; the others did not, probably because of the envelope nodes at the beginning of the tracks. Snap-to-grid did not matter. I suspect the "delete hole" option only works if there are clips on either side of the hole.
 
I zoomed way out, held down the RMB, and lassoed everything. Then I was able to slide everything to the left.

It's interesting that only the low tech trick worked. But what matters is you were quickly helped so you can continue your project.