Have a look at Mitch Seavey's Ididaride operation at http://www.ididaride.com/. Not only will all your canine encounter needs be met, but they also offer some okay looking cabins (cheap) that might fill the bill.

I personally would hire a car and drive to Seward rather than taking the train. It's an easy (and amazingly scenic) couple of hours, and having a car in Seward will increase your flexibility considerably; e.g. for shopping for grub for the cabin.