We changed up the assignments, giving both my 6-year-old , my 5-year-old, and my 3-year-old additional responsibilities. We changed the definition of a few chores (sweeping both halls is now one chore done once a day, and it includes picking up anything on the floor in those halls; it used to be part of sweeping other areas). We lightened the load of the oldest two children a bit by dividing some chores into smaller parts and giving those smaller parts to other children.
So far, so good!
There is no way that I could do everything in the house that needs to be done by myself, nor would I want to; It is important to me that my children learn to work, and to work well.
We have 6 chores times in our house. They are before and after breakfast, lunch, and dinner. Some things that we list as chores aren't really chores (such as getting dressed and brushing one's teeth) but by putting them on the list it helps the children remember to do them.
Ivory is 1 and has no chores, but we do ask her to help pick up toys when we are picking up. She usually puts several of her toys away with us.
Here is our current chore schedule:
(We then have family scripture study, sing hymns, have family prayer and the children says individual prayers. Elsa is tucked into bed while the others do their chores. On Monday nights we have family home evening, where we sing more hymns and have a short lesson on a gospel topic.)
Of course, this doesn't mean my house is perfectly clean all the time (in fact, far from it!) The floor always looks like it could use a sweep and mop. With 7 children home all day, it gets dirty quickly. Toys get played with often. Toddlers love to change clothes often. We go through a lot of dishes. Having several short chore times is needful to keep things under control.
Some additional reading:
"The Joy of Honest Labor" by L. Tom Perry (online talk; the quotes in this post are from that talk)
Managers of Their Chores by Steve and Teri Maxwell. This book really opened my eyes to what my children could do and helped me to implement our chore system many years ago.