You just need a warm spot. In a cabinet over under-shelf lights worked in my last house. I recently read you can just put the warm milk and yogurt starter in a thermos, too.
I made that labneh according to your instructions - so good!!! I loved it with dill and garlic to accompany beets. Thanks for that!
You're welcome and SO glad you did it!!!
Another way to make it is simply using a cooler box with warm water in it! They keep warm for so long and you can add some boiling water to raise the temp. That is if you have a cooler haha