I would go to key west... or some remote island in Canada. Steal a gas truck, whole bunch of explosives, weapons, food.. and womens.. Drive to an island, steal a big ass boat. Steal more gas. Blow up the bridge, and live on the island for a few years.

I really can't picture the world going to a situation such as.. 28 days later. I see it more such as the movie/book The Stand. Everything is empty and now power. You could pretty much have sex with any girl that you wanted.. until they all started decomposing.