I wasn't going to suggest it, because it sounds like a joke, but what about one or two ultralight aircraft? Pretty sure some will take off in 100 feet or so, and give you up to 100 miles or so range.

On the downside, they're very much fair weather only, a little dangerous, and you can't carry any gear to speak of. But to get off a virtual island, out of a wrecked urban area and to your suburban/mainland cache, they could be just the ticket.