I am not a flight instructor, but a student at Wings Aloft. I finished ground school last month. There were 3 different instructors (which I thought was overkill). They all seemed rather satisfied to be working there. My flight instructor is another person altogether and he, too, appeared happy with his job.
Regarding winter in Seattle, it rains more than it snows. The close proximity to the ocean means moderate temperatures.
Housing is very expensive here. The average home in Seattle is unaffordable to those making an average wage. And as I understand it, instructors do not really make an average wage.