As long as you are a PR, you are entitled to "enter" Canada. So, if you can travel to a Canadian PoE, you can enter Canada and stay. No need to wait for a decision on the PR TD. If the PR TD application is denied you can do this before filing the appeal, for up to 60 days, or after filing the appeal.
If you have not been in Canada for more than a year, it is NOT likely you would be issued a special PR TD to come to Canada pending the appeal. Which means you will not be allowed to board an airline flight coming to Canada since you do not have either a valid PR card or a PR TD.
That is, there is a difference between being allowed into Canada versus the available means of travel to Canada. In particular, for most people that means the only way to get to Canada is to travel to the U.S. and then in the U.S. travel to a land border crossing into Canada.
I do not know or pay much attention to who or how or when non-Americans can travel to the U.S. (it is *hole country I avoid as much as possible, which is not easy because I have family and friends there). But if a PR abroad can travel to the U.S., that is one of the ways a PR can get back to Canada, and once the PR reaches a PoE into Canada the PR will be allowed to enter Canada.