Just another data point, perhaps a little brighter than most: booked and requested less than 8 days from departure (both flights last week), selected dates based on business seat map and availability figures (10-20 seats open, availability in J buckets maxed out), upgrades in both directions cleared around 48 hours before departure. I noticed only 1-2 days per week with loads like this, otherwise J looked really full and certainly upgrades would be tough at best. My advice: if you are flexible on dates, wait until closer in to book, study the loads on EF, and a 1-2 day shift might make your chances significantly better.