The 6 x 5 minute session was a real quality workout. The final repetitions were faster than threshold control, so Sunday should consolidate that work rather than add another hard stimulus.
The long run does not need artificial slow pace. Based on the recent 24 km run, an easy-fluid range around 6:40-6:55/km is appropriate when the effort stays conversational and the stride feels relaxed.
The objective is simple: complete 90 minutes with steady aerobic control and finish feeling like there was still another gear available, without using it.
Takeaway. Easy does not mean slow. For this long run, use one stable pace range and protect the session by avoiding a late progression, sprints, or extra distance.
Next step. W05D7 Long Run. Ninety minutes of easy-fluid aerobic running. Settle in calmly, then hold a stable conversational rhythm without a fast finish.