I live in an apartment. I'm single and that's all I need. I drive a hybrid approximately 500 miles per month because I make a point of living close where I work. I eat meat, but not processed foods. I have a capsule wardrobe with approximately 30 items of clothing that I mix and match. About half the items were purchased from resale shops.
The thing is a "lifestyle with no car, multi-unit housing, very little meat, and no vacations whatsoever" isn't just poverty from an American POV. That would pretty much be a poverty lifestyle anywhere. Even though Americans may have the largest carbon footprint per capita, we still belch out half the CO2 and other greenhouse gases that China does. The reason China's per capital footprint is lower is because their population is 5x bigger.
It's population that's the real issue. We need to allow the world population to be reduced by half, and kept that way,. Even if everyone rides bikes, lives in apartments and goes vegan, we still cannot sustain a world population of 10 Billion by 2055. Countries with aging populations, like the US, need to deal with how to care for over 100 million adults who no longer work right now, but no amount of birthing (white) babies is going to fix that. More open immigration policies would help. But to tell the developing world, like India, that they may not expand their economy because it causes too much pollution is kind of a "we got ours and screw you if you want it too".
Too many people = too much food, fresh water and energy needed = too many greenhouse gases emitted. Lower population, greener energy sources, conservation and carbon sequestration are the only ways to roll back the climate change clock.