It's common to wait until right before (1-3 months) to figure out an in-home daycare.

Op here - thank you.

Bad ones: nap area in kitchen next to stove, lots of wires, aggressive dogs, filled to the brim with stuff, dirty, smoking in house, daycare in attic with no easy way to get out if a fire (and I have an infant)...

I did find a good one but she wants to wait until right before to give us a spot..

I am almost afraid to ask but what is so bad in the bad ones?
I am a home daycare provider, here is my advice on the timing: ask when a spot will be available. If it is within a month of when you need to begin and you like the place, sign the contract. If you have to pay before your child begins it will be only for a short time. I don't take payment before a child begins - BUT I won't hold an open spot for more than a few weeks.
I would not recommend you secure a daycare spot nine months in advance. Although some people do this I don't think it is a good idea because so many things can change in 9 months on your end and the provider's.
Finally, ask everyone you know for personal recommendations of providers. In other words NETWORK! Hopefully this will help you to avoid horrible home daycares.
There are MANY wonderful providers
Good luck.

We have a gap in care for about 8 months between Au pair and preschool. We thought home daycare. Toured a few - were horrified by some, loved another. The issue is that some daycares commit 9 months in advance and others only a month before. And there are very few spots for under 2s in the decent ones.

When is the sweet spot time wise to committ? Any tips? This is so stressful - the bad ones are just so bad!!!