You will begin your journey in Wintertusk after you have completed the "Blood Brother" quest in Grizzleheim. If you have completed this quest, speak to Merle Ambrose who will give you the quest "Cold News". If he does not have the quest 'Cold News' for you, have haven't completed the "Blood Brother" quest.
Who gives the quest for blood brother. I'm lvl 55 and i'm almost done with grizzleheim. I looked everywhere.
The thing is just complete gh to get to wintertusk dont do anyside quest since you're lvl 55 beside getting 35 xp for a side quest in gh is not good just follow the main quest you should finish gh really fast i just started gh again on my storm he lvl 44 so i can get to wintertsuk and lvl cause of all the xp i didnt get on my fire legendary