While this might seem reasonable, it is the automotive equivalent of the 'old wives tale'. A car in short term storage needs to be driven at least once a month. It requires more than just getting the water temperature gauge off of the peg. You need to take the car out for a drive for about 20 miles or a half an hour. When you go out to the garage to just warm the car up, what you're doing is raising the temperature inside the block - but the engine doesn't run long enough for the engine block to get entirely heated.
Condensation is moisture - and moisture causes rust.
A car sitting too long without being run also invites fuel in the carburetor and fuel pump to evaporate, leaving behind a gummy residue. So Dr. Hipo recommends a half hour of exercise once a month, every month. The oil change interval isn't effected too much by inactivity. Moisture can be collected in motor oil and if it is, it reduces the oil's lubricating ability. Long term storage is another story entirely.