When I moved from USA to Canada mid year in 2016 under similar circumstances, here is what I did:
- bought both us and canada turbotax
- filled out canadian turbotax based on part year
- filled out us turbotax based on full year, but claimed credit for canadian taxes paid
- submitted both, both governments were OK, although the canadians demanded some extra paperwork
Some tips:
- in canada, you only owe capital gains based on the cost of investments on the day you became canadian resident again
- you also have to file FBARs to us government
