you can make several copies of the whole track, then delete leaving sections ..
-copy 1
-delete all but first <5km or up to the first intersection
-save as section 1
-copy 2
-now delete all but the second<5km or the next segment between intersections
-delete the nodes from section 1
-save as section 2
-etc, repeat till done
-export a group of as many sections as your comp can handle, repeat with other groups as separate stages until you get to the end ..
I'm not sure how terrain is handled with this method though. haven't tried this in quite a while.
Good luck