It’s only being done experimentally in Toronto. So there would be a lot of hurdles to try to get into that study. The research is being done to try to determine whether or not children with unilateral hearing loss benefit significantly from CIs. The evidence is still not strong, so your audiologist is correct. As for going to get it done privately in the states if you have a spare $100k, there aren’t THAT many CIs that are being used and as far as I know most of what is being implanted in the states is going to be similar to what it being implanted here. But that being said, once the device is implanted it has to be maintained and re-mapped and I don’t know how you would go about having that done in Canada. Most that stuff is done for our CI users with some help from OHIP and so the CI audiologists work within that structure. As your son’s wouldn’t be covered, you’d have to find someone who could offer it privately. That could be tough to find, and also expensive.
It is probably worth making the point that this is major surgery with significant associated risks for something that we aren’t sure offers significant benefit yet.
A bone-anchored hearing aid would be another surgical option. BAHAs were developed to send sound via skull vibration for people who have a functioning inner ear but a dysfunctional outter/middle ear system. However, because they also effectively send the signal through the skull to the other ear they are an option for single-sided deafness. But again, evidence of strong benefit is still limited. The surgery is less invasive, but still surgery.
A CROS system will be an option, but not until your son is much older.
Many people do fine with one normal-hearing ear. There are certainly accommodations that should be put into place in school. Family members should be aware, and your son should be taught to advocate for himself as he gets old enough. More care should be taken at either end of life: It is common for young children to have a build-up of fluid in the middle ear that effects their hearing and therefore can effect their language development. With only one normal hearing ear, the system is missing some natural redundancy, so you probably want to be alert to times when your son isn’t hearing as well out of his better hearing ear, and see an audiologist and/or speech language pathologist if you are worried just to make sure that language comes along well. (I’d say emphasize reading together, but that is standard advice for all children always.) Once your son is in his 50s (a lifetime from now!), he’ll probably want to be alert to hearing loss in the good ear since he will be more impacted by hearing loss than someone with two normal-hearing ears.