How can 768p displays display 1080i?

[Energize]

I've noticed that a lot of 768p tvs also support 1080i but how can they do this? I know that lcds can't display interlaced material so the 1920x540 fields are bob deinterlaced and upscaled to 1920x768, but how can the tv display 1920 horizontal pixels when it only has 1366 pixels?

 

[Energize]

Why do stations waste bandwidth by broadcasting in 1080i instead of 720p then when the picture quality will likely be worse? Practically no one has 1080p displays.

 

[Energize]

Since when do stations broadcast at 1080i?

Sky hd, and there are loads in the usa.