I live 5 minutes away from a deserted Island... hop on my neighbors boat after loading up with ammo and supplies. It's large enough to sustain a couple people with fresh water source and wild fruit (oranges, citrus, etc...). It's probably 4 sq miles worth of land that is protected.
I'd survive assuming the zombies can't swim / walk through water & can't use vehicles. It's planned out and yes I've dreamed about it.