It seems you have all the advice you need and that you've confirmed that it's indeed blocked.
I bought a PCV kit for mine (2006 V70 2.5 turbo) and at 110K miles when I did mine, it wasn't clogged, but it seems that the major factor may be getting the car up to temp each time you drive it. The previous owner of mine had a 40 mile (64km) commute each way. The engine gets fully hot and any moisture in the oil is evaporated and doesn't emulsify and sludge up the PCV drain. Short drives might clog it up quicker.
Alas, the kit was around $350 if I remember right, and I spent a weekend lazily doing the work and cleaning the parts and engine as I went. I can understand if you're reluctant to do it. It's not HARD, it's just tedious. I could probably be convinced to part with $500 to have someone else so it. :D
Here are some pictures of my operation:
http://imgur.com/a/svQXo
15000 km oil changes shouldn't be a problem - I change mine every 10K miles (about 16000km) and my oil analysis shows plenty of life left in the oil. My car uses maybe half a quart of oil in that time. If you want to stick with that oil change interval, you might want to get your oil analysed once or twice at that interval to ensure it's holding up properly to your driving style and conditions.