The H1-B=>GC route to immigration does require a degree - 4 yr one is preferred but in some cases 3yr + ton of experience gets you buy. It's not guaranteed though.
Depends on the evaluation of your degree - if the degree is job relevant and evaluates to a 4yr equivalent then you might get through.
Where I come from most candidates have 4 year degrees and the ones with 3 years generally have trouble if it is not directly job related and if they don't have sufficient job experience to make up.
This is interesting. Must you have a degree to immigrate if you have a strong work history?