My wife just called to say that the windscreen wipers are frozen to
the windscreen. Its probably the result of some freezing rain, which
has been predicted for this part of New Jersey.
Can anybody suggest any way to unfreeze them, other than the obvious
run the engine and turn on the heat?

I read that you already got the wipers unstuck.

For the future, I wonder if you could prevent the problem in the first
place by parking the car in a garage or covering the windshield with a
tarp?

Just a thought...

Anthony