The video at http://www.twr.org/powerup presents TWR's plans to increase its 800 kHz Bonaire transmitter power to 450 kW, with antenna patterns targetting Cuba and Brazil. If this happens then Vancouver and the rest of the West Coast would be in the line of fire from the Cuban lobe, or could the antennas be set up for a high takeoff angle to serve just the target area, minimizing DX propagation and interference to others on 800?
How well might it be received in the Lower Mainland? Certainly only DXers would care. Japan has stations in the 400 - 500 kW class that can be heard when conditions are right. Bonaire is 1000 km closer but half the path is over land. Perhaps a better comparison would be with the Caribbean Beacon, which allegedly uses 200 kW (sometimes?) and can be heard here weakly when it does; 450 kW isn't that much more but would still help. Experience with the Carribean Beacon suggests that Bonaire would be heard here, but not every night, and would be very noisy when it is. It would also have to compete with the handful of stations already on 800 that make it here (most often CKOR Penticton).
I wonder if this will actually happen. It would be an echo of those days that mostly predated my DXing activity, back when there were more high-power transmitters in use and I had a few holy grails that I never heard because I came along too late. One of those was PJB 800 Bonaire!