Honestly if your a miler you dont need that high of mileage, especially in season. I would say quality mileage is important for a mid-distance miler type. El G only hit like 75 during his early season phases. Another more recent example is Miles Batty who only does 30 but does alot of cross training. Id say his volume is closer to 70-75 with the amount of cross training he does. Nick symmonds runs 70 miles weeks. My point is from personal experience and the examples I stated the optimal volume for a mid-distance guy is is in the 70s somewhere with relatively high quality.
Im assuming you had a cross season. so I would just go up to what has been working 80 mile weeks in december/january. Then drop it to 70-75 when you get into track season and start quality mile workouts. I would wait until you go back into summer base before cross and try to hit 100 mile weeks there if you were still going to attempt it.
Im not saying every miler should run 70 but what I am saying is 70s seems to work for alot of mid-distance runners. My philsophy is you should do the mileage that works best for you. That very well might be 100, or it might 40, or 99 or 101. You should do the amount and quality that is optimal for you. Like one of the above posters said 100 isnt a magical number, so dont get caught up in letsrun bullshit about everyone doing 100 mile weeks, most likely they are the 17 or 18 minute 5kers who run 100 themselves and will still amount to nothing cause they are idiots.