If you can visit Sweden 4 times during the year you could do the Swedish Classic? I have been thinking about it for a couple of years but have never done cross country skiing - but then how hard can it be?
I can't remember the months it's held in, but you compete in 4 disciplines throughout the year:
X Country Ski (Vasaloppet) 120km
Swim 3km (I think)
Cycle 300km
X Country run 30km
http://www.ensvenskklassiker.com/index.php?doc=14 will help if you can read Swedish, although there are a couple of English pages in there.