Device specific texture resolutions?

Unity allows me to set specific maximum width for a texture in the import setting. However, within the same category of devices - for example: Windows Phone, the memory and GPU capabilities vary a whole lot. Am I forced to assume the worst and go with the lowest device settings for texture compilation or to maintain two versions of the project or is there a neater way to go about this?

Unity - Scripting API: SystemInfo might work for Windows Phone.

I would include small/medium/big and load the textures accoarding to a % of something like SystemInfo.graphicsMemorySize if it works for WP.

Or maybe something more rudimentary like SystemInfo.deviceModel…