My part-time enthusiast’s understanding is that at higher resolutions, video RAM can become the biggest limiting factor, especially as you start cranking up the OMGFXAAs and suchforth. People don’t generally recommend trying 1080p on anything less than 1GB v-ram; I’d imagine than ?x1440 is pushing you into the 1.5GB stage for newer stuff.
While I was being a tad snarky, I did have a 24-inch Sony GDM-FW900 CRT, and the best it could do was 2304 x 1440, so I’d be a little surprised if a 17-inch CRT could get that high. VGA bandwidth would be a limiting factor, if nothing else.
Actually, with the 400Mhz RAMDAC’s in modern graphics cards and a good quality VGA cable, you can do 2048×1536 at 85Hz. Bandwidth issues are far more of a concern with digital connections. (You can get cards with faster RAMDAC’s as well, although that’s a little specialist…and you can’t combine them as you can digital connections)