ice ages didn't happen until after the asteroid strike. Antarctica moving into the south pole is likely a large part of it, but they don't really understand ice ages that well TBO. Anyhoo, the Earth was a lot warmer prior to the strike and we have been going through extinction events every 100k years.
By "the" asteroid strike I'm guessing you mean the one 66M years ago? There were definitely ice ages before that, likely including one or more Snowball Earth phases (the whole surface frozen): https://en.wikipedia.org/wiki/Snowball_Earth.
