I found myself in a similar situation a few days ago and did surprisingly well.

First, a little background. My wife and I had managed to accumulate 100K miles each over a period of years, but were not using CO much and wanted to redeem them before we lost them through account inactivity. (Another airline FF program is where we now accumulate all of our miles.)

I wanted to get two SaverPass BusinessFirst tickets to/from Scandinavia, anytime before winter or even late autumn. I was concerned because the 330-day window would have had us traveling when the weather was too cold for us. (We are Floridians.) I saw the color-coded calendar indicating availability on dates acceptable to us and simply phoned an agent who booked the tickets on the exact dates I had identified on the calendar. I was absolutely elated that it was so easy. All of this was done two days ago, immediately after the web site update had been completed and with new award seats showing availability.

My suggestion would be to "identify" your desired SaverPass seats on the calendar and phone the agent to book them for you. Good luck!