To give a straight answer, at an eventual 50-60 mpw, the OP, if real, would either get injured a string of times or run mid to low 15.
Wow that would be amazing (well not the injured thing but you know). Where is the best place to put the extra miles? Like add more reps onto interval training? Make the long run longer?
JHC, stop soliciting advice you have no plan to accept. You're savvy enough to have found this community, but not savvy enough to simply search a few historical posts on training recommendations? Do a search on summer of malmo, follow the advice for 3-4 months and get back to this thread.