I looked at AO briefly, and although they mention splitting it up over two years on the Year 7 and Year 8 Booklists, the actual weekly schedule shows all 49 lessons covered during Year 7 and the same for Year 8.
I just went ahead and scheduled it twice a week, lessons 1-15 during September and October, then a break, and lessons 16-27 during January, February, and March. I think I will save lessons 28-49 for next year. There are fewer lessons for next year, but the material covered gets more complicated, so I think that will work out.
Thanks your input, ladies.