Repeating freshman year could be a good option as well. Not sure if that’s a part of your plan but it’s definitely at least something to consider. Socially, coming in as a new grade 10 is difficult, but still doable. Many prep school students repeat 9th grade for social and academic reasons and to be more prepared for their prep school experiences. It helps with chances a lot. I got waitlisted at a bunch of schools on my first try, but then the next year got accepted by them as a repeat 9.