What is the best way to get from the Beijing Airport to Baoding with oversized luggage?

You mean Capital Airport, right? Take a direct bus to Baoding from Gate 1, 1F, T3, or Gate 15, 1F, T2. The buses depart at 10:10, 11:40, 14:10, 16:10, 18;30, and 20:10. The trip takes about 3.5 hours. The fare is CNY 95. You can put your luggage into the luggage compartment. :)

Thank you, Kate. It is good to know that a direct bus departs from the airport gates! This is good news.

Do you know whether the bullet train is available from Beijing to BD. The bus trip of 3.5 hours is a bit longer time than expected since I would have spent almost 20 hours to get to Beijing. It would be good if this was possible. :)

Yes, you can take a high speed train to BD from Beijing West Railway Station (40 to 60 minutes). From PEK, you can take shuttle bus line 7 to West Railway Station for CNY 24. :)