Fleas can live a few days to several weeks without a host. Eggs, while normally laid on the host animal, usually roll off the host and incubate in bedding, upholstery, grass, etc. Once the larvae has coccooned itself, it can survive several months before emerging as an adult.
For outdoor treatment, you can use Zodiac Yard and Kennel spray. You connect it to your hose and can use it on lawn, decking, cement, etc. Repeat in 2 weeks (eggs will hatch within 2 weeks). Zodiac also has an upholstery spray that you can use on pet bedding, furniture, carpet, etc.
The days of suffering with fleas is really over. The products available these days really work.