As a librarian, this question tickles me.
Canadian here, so I don't know if I know all the right celebrities... But I have two wildcard ideas that could be fun.
Nadiya Hussain of #GBBO fame.
Certainly one episode would have a baking challenge which adds a fun juxtaposition between her and the usual comedians - but I also think she'd be up for trying new things and thinking significantly differently than many of the other contestants.
Red Green of "If your woman don't find you handsome, she should at least find you handy" fame.
I don't know how well Steven Smith Jr., CM (better known as Red Green) broke out of Canada. He's our plaid-clad icon who uses duct tape if it moves and it shouldn't, and WD40 if it doesn't move but it should. His show ended almost 20 years ago. I think an old rural handyman would have some clever engineering tricks up his sleeve for a lot of tasks.
I heard this episode of 99pi last week. The more I think about it, the more I like nails.