Shoot, around here you would be lucky to get a tree service that could get to you in 2 months. They are booked a long ways ahead, and dealing with workers that don't want to work just like everyone else.
Make sure they prove they have insurance and are bonded.
A friend has one of the biggest tree services in our area, price of diesel and lack of labor is killing him. Some days he only has half of his fleet working because half of the crew didn't show up for work.
Says he can't fire them for minor offences, because if he did, he wouldn't have anyone working. Most of his trucks get 4-5mpg.
Several years ago, he told me he removed all the air conditioner compressors from the trucks, because guys spent too much time running the trucks for the AC.