But 36000 points is IMHO very expensive for 1 night also.

IOTW, there is just no way to get this hotel cheaply, no matter what currency you have.

The only solution to staying cheaprer in Seward therefore is to choose a cheaper hotel (such as the Swan's Nest Inn which is close to half of the BW's rate), find a hostel with open beds, or sleep in your rental car.

The problem with the coastal strip of Alaska is that in many places there's no easy way to get out of town except by air or water. So it's not a place I recommend booking your plane flight before you have your hotel arranged, I bet that's what most people traveling there do.

(Gosh, there's been several times in my travels where I've found no availability except many dozens of miles away, in the continental US. But in places in coastal Alaska, where there is no "many dozens of miles away" option, you have to much more careful in booking the various aspects of your trip together, especially for a weekend when everyone wants to get away.)

I'm not familiar with the Seward area so I don't know if you there are"driveable" towns further away that might have availability or not. (In Juneau, there is no such thing as driveable other towns, you have to fly or travel on a ship to get the next town!)