Invisalign Possible if a Baby Tooth is Still in Place?

The term is ankylosed, which means the tooth is fused to the bone. It won't move and may make the Invisalign treatment not work as planned. I would suggest a consultation with your dentist or orthodontist to see the condition of the tooth.
Invisalign does allow for the tooth to be removed and a false tooth placed in the aligners. This makes it appear the tooth is still present during treatment, and when all is done the missing tooth can be replaced.
The retained canine may present a problem, so the consultation is very important.

In a word, YES! Invisalign allows for specific teeth NOT to be moved, so depending on the position of the impacted adult canine, and the shape, size and location of the retained "baby" canine, your dentist may choose NOT to move one or more of the teeth in that area. The cosmetic issue of the baby canine may be resolved with a veneer, crown or implant after the completion of the first stage of Invisalign treatment. Once the baby canine tooth is appropriately restored, an Invisalign refinement may be resumed as determined by you and your dentist. Otherwise, get some Vivera retainers and call it a day. Be sure that the impacted canine does not interfere with implant placement if that option is chosen. Good luck!

Maybe you could get invisalign first and then leave enough space around the baby tooth to allow a normal sized crown or veneer to cover it when treatment is done.
It sounds very complicated to try to remove the baby tooth and pull down the canine. It is done with children but as an adult you may find the inconvenience unbearable.