Executive Summary
Budget for several flights to Seattle for interviews, prepare yourself to be ready to move as much as possible without hindering your current lifestyle, and write a good cover letter.
From the Perspective of the Employer
Distant candidates are problematic for two reasons:
- Interview Costs
- Start Date
If the company is on a strict budget, they won't want to fly you out to interview. If they do select you, then it may take longer for you to start since you need to move. And there's always the chance that after you move, you may not like it.
All of these can be worked around if the employer is willing.
Preempting Objections
To have your location not be a hindrance, as suggested by VM Brasseur you should definitely write a cover letter. The cover letter should address both issues.
Interview Costs
I will be in Seattle from Date X to Date Y, and Date X' to Date Y' for
interviews. If those dates are not ideal for you, I am flexible and
willing to work out a schedule so that we can meet up face to face.
This is much cheaper than moving there, and will have the same result -- you will be available for face-to-face meetings at your own cost, so they don't have to worry about it.
Start Date
I am available to start work from Date Z.
Let them know in advance when you can start work (factor in the notice period at your current job, and the time required to put your stuff together for a 2-week business trip to Seattle). The details can be worked out later, but you are telling the employer up-front that you are already thinking about when you can start to eliminate that concern before they can bring it up.
Economics
If you move now, you will need to decide where to live. Since you don't know where you will be working, either you will limit your job selection based on where is easy to commute to (limiting your choices), or you will need to move when you find a job (which will cost more money and take time).
If you budget for several plane trips out for interviews, and then for a week or two in a hotel or furnished apartment while you do apartment hunting on the weekends, you will have more flexibility for less money (and if it doesn't pan out, you aren't limiting your options of returning home).