@biermanl, It sounds like you are breaking up unit 4 and 5 and mixing them together a bit - is that accurate? That timing sounds pretty good to me. I am just starting unit 5 now but I think I am WAY ahead. I will need to circle back and do a bit more with unit 4 at some point.
I would take a look at your calendar and do some backwards planning with the 20 hours for the explore/create in there as well (along with spring break, if your district has it).
Right now, if you are done with units 1-3, that seems very much on track. I always fall back that portions of unit 5 can be assigned for homework, or you can skip part of the longer projects in that unit if you are crunched for time, BUT right now it would appear that you are in a good position. Without knowing your school (what your breaks are like, how often you see your kids, if the course is offered all year or only part of the year… etc.) the best way to really know where you stand is to look at the calendar and plan it out. The fact that you are thinking about that now, versus in April, is amazing!