I like your plan and it was something I was thinking about--if you called him and he was grumpy (and that could be because of a bad day, not you), what type of impact would that have on you? Would a bad phone call do more damage than none at all?
But if you go at it with the mindset that this is an experiment I'm going to do, I'm going to call him and be real excited about everything I'm learning and the new person I'm becoming, and if he doesn't respond well, then I won't call again, I think that is a real healthy plan.
Kudos to you for all you are doing. Will you have internet service while you gone or will we be missing you too?