hi daniel-san
this is the link: (stated that hamanasu from sapporo will not available on 14dec 2014)
http://www2.jrhokkaido.co.jp/global/english/ttable/08.pdf
but in this new link,is stated that there will be hamanasu with changes of schedule~
http://jprail.com/travel-informations/seasonal-trains-schedule/suspension-and-schedule-change-of-overnight-trains-hokutosei-cassiopeia-and-hamanasu.html
"Arrival time of Hamanasu at Aomori will be changed on the following dates:
October 6, 9, 16, 25, 26 and 30, 2014
November 2, 3, 7, 9, 10, 13, 15, 16 and 19, 2014
December 6, 7, 14, 21, 28, 29, 30 and 31, 2014
January 7, 8, 9, 15, 16 and 17, 2015
Hamanasu will arrive Aomori at 6:15. Originally Hamanasu arrives at 5:39 and connect to Hayabusa 4 (06:17 / Shin-Amori). But you cannot catch Hayabusa 4 from changed schedule of Hamanasu. You have to take Hamanasu 8 (6:49 @ Shin–Aomori).
so,is it safe to assume that there will be the night train on 14 dec?
thanks for your respond ^^