Last Day To Register for the St. George Marathon

I have been going back and forth as to whether I will be in good enough shape by October to run the St. George Marathon and have a decent shot at getting a Boston Qualifying time.  I would have five months.  I ususally use the Hal Higdon training plans, and those are 18 weeks, 4.5 months.  So I would have 4-6 weeks to get in good shape in order to start the 18 week training plan.  The big question is can I take the 7 minute pace that I can barely do three miles at right now and stretch that out to 26.2 miles by October third.  One would think, ok, every week just run one more mile at seven minute pace and you should be at about 22-24 miles at seven minute pace by October 3.  It doesn't really work that way, but good idealism.  I have until about 11 p.m. local time to decide.............