Half IM to Half IM training question...

I just finished IM FL 70.3 and will soon be enrolling for Augusta 70.3 (4 months away).  I did a standard periodization training plan for my last 2 HIM's.  My question is, should I begin at the base period again or should I jump back into the build period since my fitness level is already there?

I know some believe that I should go back to square one to allow my body to adapt but I really don't want to go back again on the easy phase.  I've upgraded my plan and will be incorporating much longer bike rides throughout the build and peak phases.  The last two events my max was 3:30 rides 2-3 times before the HIM.  My new program has me doing about a dozen of those up to and including 4:00 rides.....