I have done something similar, by only printing mums and dads to me and the wife, and continued with that, I can get the whole tree on 8 x a4, then separately i have 2 or 3 sheets with all the kids from each family's, then the whole thing is stuck to wallpaper lengths for ease and so i can add people and dates as they come in, then i reprint when the whole things looks messy with my scribble.
regards
Drifter
Keeeep searching