Unfortunately dealing with an alcoholic parent for the past almost 10 years is not a very strong reason especially since I imagine the alcoholism didn't start as soon as you applied for PR. If you were able to get married, be partners in a business, do any form of business or personal travel, etc it would be hard to show that you were unable to move to Canada. Was your wife a PR as well because that will also be an issue? As
@zardoz mentioned, apply for prtd with H&C reasons and wait and see what happens. Think that is what the caller may have really meant is that by applying for prtd it will trigger the H&C review. The only way you could enter was by land at the Canadian border.