Indeed. I'd only be worried about Carl or the other girl growing like Atlanta weeds in that time.
I'm sure that they'll build some natural breaks into the story to allow for the passage of time. Through eight episodes, we've passed through, what - a couple weeks since Rick woke up? And maybe three months since the apocalypse started?
My wife and I observed that this show has yet to actually introduce clearly BAD people. With the arguable exception of Merle (who's more just an asshole than an actual baddie), everyone we've met so far are not really evil or a villainous type. They're all just survivors, not power-mad, greedy, or subject to a variety of bad-guy stereotypes as most zombie movies have given us. I find this pretty refreshing - pretty much anyone who would be the typical early victims early on in a zombie apocalypse are already dead. There are no cheerleaders, no jocks, no corporate bigwigs, no soldiers. They're all neural chow.
All we have left are the ordinary people, and as Rick said early on, they're all just white or dark meat. I know that in the comics some villains are eventually introduced, but so far I'm loving that the only theing they're doing so far is trying to survive. Something like spending 3+ episodes stuck on a highway close to an infected town while ont he way to a place they hope WILL be their salvation would never be done in a zombie movie. It's great.