Partner up with a colleague whose teaching style is similar to yours and split the work of tweaking the official lesson plans!
I think this is definitely more of the reality in high school at least. We don't usually have 5-6 people teaching the same class as us, but there might be 1 other teacher teaching a few sections of your class or who's teaching the honors/CP version of your class. I think this is why HS teachers often find co-planning difficult, but you can effectively co-plan with just one other person and still split your workload in half.