Full Experience:
The officer at the first booth asked me if I will be returning back to US, I said yes. He seemed fine and sent me in doors to get COPR validated. The officer inside was very polite but told me that I can either quarantine or go back without landing. He was very nice and apologetic but firm. I told him quarantine with a kid is difficult but nope.
On day 3 I came back to US. On day 5, (5 mins back) I got a call for quarantine screening and explained my situation. They said it's totally fine.
I would suggest don't panic if you are asked to quarantine. Just say ok and still take the u turn. Answer your quarantine call and tell them that you just went back. Everything is chill.
It's legal to leave. You aren't a danger anymore. Click on without symptoms and leave Canada links within this:
https://travel.gc.ca/travel-covid/travel-restrictions/isolation