I'd back off on the commute as a workout for the next couple of days. My best rides have come when I was on travel for work the week before a century, and forced to take some time off the bike. An easy spin (50-10 miles) the day before, and all that frustration that you didn't get to ride this week comes out on the road -- power! Conversely, when I ride up to the day of the ride (normal commuting, no extra stuff the last 3-4 days), the big day doesn't usually go so well.

Spin easy. Relax. Go to the movies instead of the brewery. Ride strong on Sunday!