With a passport from the UK, you will almost certainly be let in without having to say anything about dual intent. Still, it is best to have proof with you just in case they ask. Proof of enough money in your account for your stay is a good start. I would have a return ticket, which you will probably need to get on the plane anyway. Show any ties to the UK you still have - an apartment, property, bank accounts. Also bring proof of your PR application and the sponsorship approval letter.
For the people who need TRVs to get in, you will probably be denied with a PR application in process. Note Frolic's wife got a TRV by leaving her son behind. Leaving a child behind is very good proof you will be returning to your country, but is not an option for most.
For countries where people need a TRV to enter Canada, the visa officers are very suspicious and do not seem to pay much attention to the 'dual intent' rules. There is no harm in trying, but gather as much proof as possible that you will leave Canada at the end of your stay.