My wife is an immigration consultant with her own license in Canada. Here is what she said to me when I asked her to read your question
of course he can just come in and visit temporarily. that’s nothing to do with his working holiday visa. he will only get a work permit upon entry when he shows his visa approval letter to the immigration officer. Every time when people enter canada, officer will ask for the purpose of this visit. Depending on the purpose, officer will decide if the person should be let in directly or directed to the immigraton office to get papers
So you have got nothing to worry about, state your purpose clearly and there is no need to show your acceptance letter.
If you have your return ticket, and tell the immigration officer that you’re visiting as a tourist now and come back on the visa later, there should be no problem.
In fact, if the working holiday visa is on a separate piece of paper that is not attached to your passport, you can leave the visa at home (or better: take it with you, but don’t put it into the passport, so you have it available just in case), to reduce confusion about your immigration status.
Credit:stackoverflow.com‘