4kids1wife,
MHR appears to be an advanced athlete. For your 1st half, you might want to cut back on his recommendations. I personally wouldn't wait till after Boston to start training for the half. Another thing that you might want to consider is NOT going all out in Boston. Sometimes it can take 4-6 weeks to COMPLETELY recover from a long distance race. I wouldn't want you to have a
PR race and then spend the next month recovering, in stead of training for your half.
I have heard of people who have completely trained indoors for a half before. but, I too am weary about doing such things, and would suggest getting out whenever it is safe, hopefully you will have plenty of good weather in May for that. In the mean time, I am indoors training, as if I were outdoors, simulating hills with different resistances.
Good Luck!
Mike