i dont know about the island method. i live in the high desert of north west az. and i have a couple of choices depending on the time of year, size of the outbreak, and the people that are in my group. you have to plan for your personal situation. know the area that you live in and find alternet escape routes. the most obvious will be cloged and unpassable. know the local plant and animal life. it does no good to get away from the hostiles if yo u die from not eating. and drinking posses another problem. when it gets hot you need to drink plenty of water, anything with alcahol or cafine will dehyrate you faster then you can drink. there are a lot of diffrent things that you have to consider to form the best defince for yourself. let me know if you need help, i might be able to assisst you.
I have a pretty good house for zombie defense. Not too many windows, the only bad thing is I have two huge sliding doors. I'd most likely use my scrap wood and scrap materials to build a type of "barbedwire" to slow the zombies down, Otherwise I could set up a wall defense and have a sniper position on my very flat roof. I have a two story also so I could destroy/barricade my stairs and make a rope ladder to climb up and down, after all what could the zombies do with no staircase? Mainly my neighborhood is quiet. I have lots of resteraunts and gas stations just down the road and it's heavily populated. So looters and zombies would be just down the road. Id most likely just lay low for the first week with my two buddies and let the looters get killed/kill zombies and the looters to clear out of the area. Then, the searching for supplies begins, I'd most likely have a team of 3 or 4(yes I know, like left for dead, LoL) I have about 4 friends who live in my area very close, so it wouldnt take much. I have a 12 guage and just recently discovered an m16 with two clips in my basement behind drywall. my other friends total up to a revolver, .22, muzzle loader, shotgun, and a winchester type weapon that you cock the tigger gaurd and he has plenty of bullets for it. We'd be fine for weapons, food also, I have a pantry in my hosue that is usually stocked with canned goods and other food. we would have 6 CB radios from my basement. our main control pannel for the two security cams I would have set up is in my room. and we would have obsticals in the yard surrounding the house, from the top of my roof we have a whole neighborhood veiw. So defense is easy. scavangeing.....harder. I know that my neighbor is a cop and the house is now just a vacation home and he leaves 4 weapons in his house, and they arent locked. He has a standard issue police pistol with 3 clips, a type of shotgun, some scoped semi-automatic rifle(most likely our sniper rifle we would use) and I think its a MP5 with 2-5 clips, he had so many clips, so its hard to tell. Hes part of our swat and he patrolls our streets when he used to live here, now hes gone so the weapons are for the taking. so theres an idea of my defence and scavange plan.
your absolute best chance is to find a old prison with high concrete walls in a city there probably not gonna be bow like res ev 4 after life to breack it down so i like that idea and if zombies are massing alchohalic molatovs will burn them and make them die and decay so you would eventually be able to get out if the city isn't massive like la or something because there are only so many zombies within a hundred mile radius so prison with big walls seems like best idea