As far as the audience knows, this outbreak, or whatever it is, could be limited to a few parts of the USA. It would be interesting to see some other parts of the country, or even some other countries. Is this something that only happened to the USA and the rest of the world managed to avoid it? Is this a worldwide problem, with very few humans left alive? Broadening the canvas and making the show about slightly more than just one rag-tag group should increase the potential for new characters, new plot threads and new opportunities for tension, not to mention a few more gruesome deaths. This wouldnt have to be some Resident Evil-style trip around the world, but seeing some other countries and how they cope could leave little breadcrumbs for where the show will go. Besides, this is a programme shown in 120 countries, so having some chance of spotting local landmarks will widen the scale of the show as well as let worldwide audiences see a piece of home. Albeit, a piece of home that's utterly desolate and covered in the undead, of course.
I.T. Consultant, technophile and Doctor Who fan. I like to talk about tech, take films apart and make excuses for Doctor Who's continuity errors. No other show has the power to make me feel like a big kid.