ok i think you are an express entry applicant by the way i am working for the same employer for almost 4 years now here in Saskatchewan
How does it matter if you are working for the same employer for 4 years or 1 year - if you dont have PR or COPR and you have not landed?
If you are landed immigrant then you can do anything you want. As I read from your post that you are waiting for PR stamp in your passport. At the same time you want to resign ASAP even before receiving PR stamped PP or landing.
If you resign prior to landing - the officer at the border can ask you current employment documents and if you tell them that you resigned then the officer can ask for supporting funds...and lead to many questions.
You seem to be very smart as you are working here for 4 years in Saskatchewan and you should have figured this out and you dont even need to ask a question here in the forum. Please dont waste others time (we have already our things to worry about) and yours (you may have lot of free time working in Saskatchewan).