Personall..(for me)...11 hours would be out of the question no matter what the cost is. Getting up to be ready by 6:30 means you are up probbaly around 5:30 to get ready, get the home ready, do breakfast for your own kids, etc
And anyone staying to 5:30 really does cut into your family time and activity time.
This is not just for 1 month or two month but potentially for 3 years that you would have to keep these long hours.
Stick with your guns and what you feel comfortable with. The reason you are doing home daycare is partly because you can DECIDE what YOU are comfortable with and if it doesn't sit well with you then don't get into the situation to begin with
I think 8-10 hours is much more manageable.

The thing with homedaycare is that our day does NOT end when the children go home. Once the dck leave we have about an hour of vacuuming, cleaning, cooking, etc plus then chores for our own kids so it makes a reaaaaallllllly long and draining day sometimes.