1.5 mi Intervals 7:05

I ran 3 intervals in 1.5 mi today at 7:05 pace. I ran 1.5 mi out at 9:33. I want to increase the two interval workouts to 2 mi next week and limit my easy pace warm-up to 1.5 mi. I ultimately want my interval workouts to be 3 mi with a 2 mi warm-up. I could substitute a hill workout for one of the intervals while doing races, long and tempos on the weekend. I am enjoying the rush from 2 intervals a week for the time being.