It depends on the crew and apparently your contractor’s crew is unprofessional and small…
Having worked in the home building business, the people who tell you how long it will take are not the same people driving the nails. It could take two months if you have a good contarctor with good subcontractors, but I would guess six months with most.
Ask your contractor to speed things up, or you will hire another to finish the job.
It sounds as though you have one of those great contractors who work on multiple jobs at the same time, instead of one at a time. My brother and I do contracting and remodeled a 2000 sq ft home and did the landscaping in less than 4 months. Even when you have a bid, it seems very unprofessional of them to take this long, unless they have run into every problem imaginable. Next time try to build into the contract a discount for the project running over a certain amount of time. I have done this for my customers and have never had to pay out for it.