Some might have tough schedules or other reasons not to drive all the way to Finland. One option is then to pack the motorbike and accessories to a container and get it shipped to Finland. Then you can have a flight to Helsinki or Tampere, pick up your bike and have a ride to the rally event.
Here is a short list of some Finnish companies that have this kind of service. You can find your local suppliers by just googling ‘motorbike transportation’ or ‘motorbike cargo’.
https://www.niinivirta.it/home_en specially from Milano, Italy!
http://motologistica.fi/#palvelut specially Vicenza, Italy; Barcelona, Spain; North Weald, England
https://rajamaki.info/our-services/car-transport.html specially Costa Del Sol, Spain
https://www.tjllogistics.fi/yhteystiedot specially Fuengirola, Spain
http://www.scanlink.fi/de/ specially Glinde, Germany