We use elements of CC Memory in our co-op. We spend 2 weeks on each unit. Last year we mostly reviewed memory work during morning snack time and listened to the CD in the car. So we spent 15-20 minutes 3-4 times a week plus co-op day. My sons were 5 and 3 so I couldn't do much in the way of reading and writing. With an 11 year old, you could do much more using it as copy work and such. Include the 3 year old too - it's amazing how much they can pick up just by being around. we're musically inclined and found it easier to learn the Latin by singing the chants.
Doing it with a co-op is easier than I imagine it would be to do it by yourself at home. Even if you had one other family to meet with once very 2 weeks to present the materials together , that would be nice. Otherwise, if by yourself, it might work to make a schedule for yourself - I.e. Monday: Latin and Catechesis, Tuesday: math and poetry, Wednesday: Science and history, etc. Present everything one week and have much of it posted on the walls or in a binder for review. Then spend the 2nd week reviewing everything.
Just some ideas. I think it's a wonderful collection of memory work!