Hi.... And congratulations for making this lovely decision... I must say it was one of my best trip in US...

MUST DO:
Pack warm... I mean really warm... 2-3 layers of thermal... Warm sweater (cashmere type - light and warm)... Avoid multiple jackets as it will make manuavering difficult... Carry some heat pads (disposable's are better) / ear warmers (life savers for us) / monkey caps / good snow boots...

Chena Hot springs is a must... I know it is expensive... Don't take any of their expensive tours... Take your swimming costume... Don't miss this...

Avoid driving ANC to FAI... too risky but if you have been living in cold areas then you will be fine... don't expect a lot from this drive...

Barrow is not worth more than a day... For me the experience of -39 degree was the kicker... :-)...

Thanks,
-Deepak