Re: remote switch

The technology already exists to allow activation of a power-turnout from a locomotive cab in dark (unsignalled) territory. The activation is confirmed by a wayside signal, and fail-safe measures prevent accidental activation of the turnout as a train passes over it. The relatively low-cost system is know as FAS-PAS. It's used by KCS and a number of shortlines, including the Western New York & Pennsylvania, which installed two FAS-PAS units on a siding at Columbus, PA. a couple of years ago. We've found it reliable and practical.
While FAS-PAS is a little more sophisticated than your "garage door opener", it employs the same principle. FAS-PAS is made by Global Rail Systems of Marlin, TX.