To TheRealCanadian - Very eloquent and professional response. Hats off.
People do need to understand that "Permanent Residency" in the country means exactly that "Permanently Reside". Someone cant permanently reside in multiple places at the same time. When OP used word "have to", it needed clarification as USCIS views (when deciding if PR is valid) compelling reasons to stay outside country differently from "let me go establish residency in neighbor country so I can get free/cheap health care and get to keep PR of both countries".
Same is going on with DV Lottery. People enter it willy-nilly and start worrying about how much it costs, whether its worth etc. A good soul even opened a thread advising potential DV candidates to think hard before entering.