Yes, this is a great idea. I bought a mountain bike not long ago with dropouts that I can convert to a SS in the winter.

As people will say, cables and derailleur will simply not hold up in the freezing rain / salt. Removing all cabling on the down tube (gearing cables) which are most prone to wear in the winter will seriously improve your ride durability.

I did one winter on a hybrid and the salt ate it up. I did another winter on a SS bike w/o problems. That bike had 700x25s that I didn't like on ice, though. So for me it is going to be SS Mtb this winter. Also a BA rain bike in the mean time.