I've fully torn my MCL. There was actually no pain at all with the initial tear, just a loud pop (think cracking your knuckles). It got very swollen, very quickly, but the pain only really started the day after.Often with fully ruptured MCLs you see the injured person in intense pain. While Kennedy looked very sore he wasn't writhing around.
Guessing there is some torn meniscus to complicate things
I was in a knee brace for about one and a half months and fully healed at 3 months.
But I'm not an elite athlete, so numbers will vary here.