Hi LW-
I echo the "listen to thy bod" statement!!! Esp. with knees! When they start barking it's time to back off a bit or you won't be racing at all!!
I would also suggest doing the real long stuff (15+ miles) only every other week. You know it may mean that you only get one 20 miler and maybe one more 18 in, but your legs will have more time to recover.
I've got 4 marys, plus an Ironman mary in the bag, and I've certainly gone through some trial and error over the years. I've found that if I go long one week and then the next week only run 10- no more than 12- I am fine. it seems to give my legs more time to recover, but I'm still getting my body used to the endurance I'll need in the race.
I've also found that I can't run more than 2 consecutive days in a row. So maybe alternate regular running one day, with pool running the next.
Hopefully this helps.
Oh- and good job on the ice baths!! They are SOOO important!!
Train smart and stay safe!
Denise