Thanks for all the great replies!! Some very good tips and experience, I knew it was a good idea to ask!!
I didn't mention I have some good winter gear leftover from spending a couple winters in Prudhoe Bay, AK flying helicopters, but thats a little different than this trip (helicopters were a little drafty but had great heaters!). Still have my insulated coveralls, they work well over regular clothes, and easy to open up and ventilate a little, or remove altogether (at a fuel stop anyways

) if the temps cooperate. A pair of wool socks and my TNF insulated boots should take care of the feet, Neck gaiter and baclava (don't really like those but I'll use it if its cold enough). And of course my insulated leather helmet, that might be supplemented with a big beenie type hat if I can find one. Oh, and I just learned the airplane has no heater!!!
Never knew about electric heated clothing, thats a great idea for the future but looks pretty pricey for a one time trip...wouldn't have time to get it anyways. I really don't think the temps will be that bad, I just won't really know how it feels until I'm already on the way! Better to plan for the worst, and hope for the best.
As far as the flying aspect goes, I've got the Foreflight app on my iPad and will use that for planning, and have my Garmin 396 for the nice pink line. Haven't really used Foreflight yet in the air, seems pretty straightforward, and this will be a good chance to really find out what it can do. Don't plan on any more than 2 hours between stops...airplane only has 19 gals useable and since ive never flown it before, I will be very conservative with the fuel.
Thanks again for all the great advise, and I'll definately try to give a good trip report with pics when I'm done!