Awards are available on almost any flights intra EU and Scandinavia but Business Class awards on the long haul routes can be a tough find no matter the season.
For me it has been far easier to find award availability on other *A-carriers between Europe and the US.
You can always drop Eurobonus member service a line (if you are using SK miles?) and ask them to check availability for you.
As awards are cheaper with SK (less points, no YQ) I guess they are popular with SK-members (as opposed to standard *A awards).