(Not so) Long Run

Plan: Original plan is 2 miles easy, then 4x 4:00 hard, 4:00 easy, then easy run until 6 miles.
Actual Mileage: 4.75 miles of running.
5-10 mins walking warm up.
16:00 easy running, building to about 4.5mph
4:00 5.8mph, 4:00 4.5mph
4:00 5.8mph, 4:00 4.5mph
4:00 5.8mph, 4:00 4.5mph
4:00 5.9mph, My 'cool down' on the run was starting at 5.0mph, and then going down 0.1mph ever 2 mins until I hit an hour.

Route: Treadmill. The only time I could do this run was at the crack of dawn.  It's too cold to be outside so I was on the mill.  I had to start work pretty early as well as well.  Due to timing it's a shorter mileage than prescribed but the 'meat' of the workout was done properly.
High Points of the workout: I was pleasantly surprised by this workout. It was one of those "I could do this all day" kinds of feelings.
Struggles of the workout: Well, the hardest part of this workout was last night, thinking about waking up in the morning.  Not even going to lie.
I learned: This was a real boost to be able to run hard but not get so tired.
Next steps: Try it outside?
Bonus: My 'back up' plan if I couldn't get up had been to do this before the snowstorm outside.  So glad that didn't happen because that wind outside was frigid.