Some fairly strange ideas from some folks posting in this thread!
If you want to wear out a block and turbo in particular, change the oil far too often. A study of UOA results will show that most of the wear occurs during the first 1000 miles of a 3000 mile OCI. There are several reasons for that, firstly modern oils contain a lot of good detergent additives and the new oil tends to attack the layer of anti wear additives deposited by the old oil faster than it can bake on a new layer. Secondly cheap standard oil and air filters are more efficient when dirty, although in the case of the OP, if he wants to do an annual service it would make sense to change the oil filter every second year.
I do 2 for 1 oil changes and the results from the second interval are slightly better than the first. Never try and drain a spin on filter if you do want to be a 2 for 1 person, as you might start an oil leak from the seal.
Oil and filters cost money and use up natural resources, so wasting them does not make much sense.
Condensation is not a factor in terms of oil life in an engine, it is minimal even in a tropical rain forrest country like the Congo and evapourates off very easily. Anti freeze contamination from a bad HG is far worse as it reacts with the detergents in the oil and stops them working (That causes sludge).
The old one year OCI was based more over concerns for the oil filter oil seal and potential Silicon (Ultra fine sand) contamination in dry desert areas. If you use a certified OEM standard oil filter, the seal will be good for a lot longer than 2 years. So I would recommend using a real good oil filter (Main dealer, Bosch or Mann). In fact it's worth using a long life one if available from Mobil or Amsoil.
One poster mentioned using a major brand 0w30 and I also agree with that idea, as it does get a tad cold up North.