Before it gets cold outside, jack up the passenger side and take a better look at where you think the oil is coming from. That location is very close to the oil pump and oil cooling lines, under the timing belt. The O rings could have dried out and cracked.
I have a problem with people who start cars for 10-15 minutes and then shut the engine off, thinking they have done the car a favor. The idle speed does not splash oil over the crank shaft and the oil pump does not produce enough pressure to properly oil the entire system. You wind up with engine hot spots and sludge in the colder spots.
If you are going to park a car for a long time, change the oil and tranny fluid, disconnect or trickle charge the battery, and park it. Cover it with a dust cover and forget about it. When it is time to use it again, add gasoline stabilizer, pump up the tires, and drive.
Remember to inspect the S belt and T belt, they may develop cracks from being in the same position for so long, and dry rot.

Klaus
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1975 164 w/173,500mi 1995 850T w/91,000mi, 1998 V70R w/128,000mi