Ok, so I haven't raced in a while, but I did this workout with my XC team. It is our staple workout and is very challenging. I am not a spammer, we actually do this in high school.
2 mile warmup
1200 (70-80-90 for each 400)
5 minute break
4 mile time trial on the roads
10 minute break
1200 (80-80-80)
5 minute break
another 4 mile time trial
10 minute break
1200 (90-80-all out)
2 mile cooldown
It is about 14 miles total. I ran the 1200s close to the times posted above, and my 4 mile segments were 23:02 and 22:50. What do you think I could run for a 5k right now?