I'll be the lone voice of dissent in the crowd. I start all my engine powered equipment regularly year 'round. As far as letting the engine run until it reaches operating temperature to boil off moisture in the crankcase, you'd need to work it hard for a long period of time and even then you still would never get all the moisture out of the oil. I can tow a travel trailer from Kalamazoo to the Big Mac and find condensation under my oil fill cap.
In my personal experience and the observations of others, the worst thing you can do to a piece of equipment is let it sit unused for any period of time. Start the tractor, drive it around the yard a few laps, whatever and everything will last longer. Anything with oil in it gets splashed around, the film of rust on the belt pulleys gets polished off, tires get flexed, brakes get smoothed off, many, many benefits that far outweigh the alleged pitfalls. Ever hear anyone pi$$ing and moaning about their 4 wheel drive not working right on their truck? It's because they don't exercise it regularly. I purposefully drive a few laps around my yard switching from 4 high to 4 low several times to keep things working smoothly.
The old Farmall C is stored in a dry, enclosed pole building 60 miles from my home so I can't get to it in the winter months. In the spring I have had the clutch friction disc seized to the flywheel on a couple of occasions due to lack of exercise. I can get it to break loose by starting the tractor in gear and by the time I get it out of the barn it's working fine again...try that with your fancy safety switches that protect you from yourself.
At work we have a monthly PM activity to visit every electric motor in Central Stores and spin the shafts a few revolutions by hand.
The next time you visit the car dealer, ask about the term referred to as "Lot Rot."