The only way to get to [[w:c:wow:#|Frosthold]] in [[w:c:wow:#|Storm Peaks]] is by flight, so at level 71, you would have to have a flying mount and get a from a level 80 main on the same account. Or, as with nearly any other place, join a [[w:c:wow:#|warlock]] with a in a party of 3 or more (2 people with the warlock already) who is already at Frosthold to use their [[w:c:wow:#|Ritual of Summoning]] spell and summon you there.