I recently saw a post about satellite photos (hat tip to Tom). I figured out the link, and I was able to get a satellite photo for Jan. 18, 2013, for the Connecticut River. By placing the cursor at 42.76 N and 72.51 W on can locate Vernon. One sees no open water north, and one can follow open water all the way to the Sound. Of note, Quabbin is visible, and the water is open. This satellite photo corresponds to the time when I took one of my favorite photos of the thermal plume. Of note, the average temp of that Jan was 26, just above average.
Next, I found a satellite photo for Jan 15, 2014. It is again shows the same features of ice to the north and open water to the south. There is open water on the Quabbin.
I found a photo for Jan 15, 2015 showing ice north of Vernon, open water south, open water at the Quabbin, and, surprisingly,, frozen water south of Middletown, where the river leaves the river valley.
A satellite photo from Jan 30, 2015 shows that the lower Connecticut and the Hudson river have started to freeze over. The month of January 2015 was cold, but not nearly as cold as Feb 2015. This photo supports my hypothesis: freezing of the river, after the shut down of Vernon, lead to freezing of the Connecticut River.
Finally, a photo for Feb 13, 2015 shows that the river is largely frozen.