As an Indian in US on h1B applied GC and I recently became Canadian PR 10 days ago. I am completed the Canadian requirements and came back to US for H1B. You can follow below steps.
Here is what I would suggest:
1. Keep your GC alive and active make sure to spent 6 months after I140.
2. In the mean time apply for Canadian PR. Get approved.
3. Complete the landing process this makes you a Canadian PR. Come back to US (if you still have your H1B job and want to continue for a while.
3. As per your convenience move to Canada in minimum 1 day to maximum 3 years. Why? To keep canadian PR you need to be physically be present in Canada for 2 years. Thus max you spent outside Canada for 3 years.
4. Spend in Canada 2 years to keep PR or 3 years to get Citizenship.
5. Get Citizenship to apply for TN visa where you can work in US if need be.
6. Since your I140 was approved in step 1 and you completed 6 months no one can revoke your I140/priority date. Since it is ties to you and not your employer. So even if you go to Canada to complete physical stay requirement it does not bar/revoke/rescind your GC application.
7. Wait 50 years (or shorter if priority date become current sooner
). This can be done as a Canadian citizen waiting in Canada or working under TN visa in US.
NOTE: US and CANADA are two different countries and applying for one does not stop you from apply for PR in other. Do not let others tell you otherwise.
Good Luck. This is just for understanding and not legal advice. For legal issues take help from legal reps to help you through this process.