I've actually lasted over a week as a lone wolf (until a server wipe). Building as far away as possible and being careful around resource areas, radiation zones, air drop destinations, etc.
At the moment, I'm one of those "friendly" types who share my stuff and never KOS. My suggestion is to make friends and/or work something out with the clans.
Oh cool, well you give me some sort of hope at least. Just pissed I was ready to experience the game after 4+ hours of playing careful and lost it all and I'm back to the beginning. Makes it hard to want to play with this sleeper mode on because I'll lose everything again.