Making the right childcare choice for Lucas

Fred and I have decided to take Lucas out of the creche that he is attending now. I have 2 weeks to my DILF examinations which is crucial for my visa renewal in France so we are going to see if we can get MIL to babysit. As Lucas has another bout of cough and cold, I will stay home from school tomorrow - yes, another excuse not to send him to the dreaded creche.
Since Lucas went back to the creche after the Christmas break, we found that his caregiver has changed to another caregiver - the same one that complained relentlessly about Lucas everytime she sees me or Fred. The change in caregivers actually happened before the break but as Lucas was missing quite a lot of creche time due to his bouts of coughs and colds, it wasn't until he went back after Christmas break that he didn't seem happy or excited to be there.
Nowadays he screams and clings to me when its time to leave him at the creche and whenever I arrive to pick him up, its always to find him crying, sometimes in a corner alone like today. My instincts tell me to take him away and I spoke to Fred who came to the same conclusion - that maybe the creche is not a suitable place for Lucas and that the caregivers are overwhelmed and shorthanded as there are too many kids.
The limit is 20 kids a day, but there were only 3 caregivers today when I picked Lucas and one of the caregivers was the principal of the Garderie. Lucas stopped crying immediately when he saw me, he ran to me and after I picked him up, turned to everyone and waved goodbye. It was like he couldn't wait to get out of there!
Today that alarm went off in my head, and I am not going to ignore that bell. We will look for a private creche (in a qualified nanny's home, with references) instead. For now, I will take care of Lucas myself, but while I am still obligated to attend my compulsory classes until April, it is going to be a juggle. Fred will speak to his mother tonight and I am crossing me fingers that she will agree to help us out until we find a nanny for Lucas.

How do we know if we are making the right daycare choice? Especially with a non-verbal toddler like Lucas it can be quite a challenge because he cannot express himself and is unable to tell me how he is adjusting in creche. But while it is normal for toddlers to cling to their parents during daycare drop-offs, this behavior should improve over time - with Lucas it has deteriorated instead. Toddlers who are happily adjusted to the creche should stop crying shortly after their parents leave their sight and settle in to another activity. Lucas' crying seems excessive at drop offs and does not seem to get better over time, for me, it is enough to conclude that this creche is not a good fit for him.