Zhurh would be the one to seriously take advice from since he's in the same state and knows the size of the critters up in your area.
I know the alaskan meece
are larger than the ones we've got here in the upper midwest states but I don't know exactly by how much.
Both .270 & .30-06 are very common calibers to use on them around here...except for those few "overkill" guys that run around with .338Mag and larger trying to shoot their animals from a 1/4mile away.
For what it's worth though, if you're currently using the .270 you're not gaining much by loving up to just the .30-06. With the .30-06, you're gaining a heavier bullet weight selection but really aren't stretching your range out any appreciable amount.
My recommend would be to move up to one of the belted magnums like the 7mmRemMag or 300WinMag.