I'd go for the earlier (or even day ahead) arrival. Too many uncertainties for the short connection. While 3 1/2 hrs would be plenty of time in your above worse-case connection scenario and even 2 hrs may be enough, you don't have anything more than 1-1.5 hrs wiggle room in the event of a delay or unfavorable schedule change. Rush hour should be long over when your can comfortable aim to check in for the QR flight. Problem is what to do with your bags.