There is some hotels on the 520 Highway and one of them could be affordable: the one on the North side, old Quality Inn.
There is a Days Inn at the corner of Cote Vertu and 40 Highway.
There is the Motel Pierre in Ville St-Laurent on Marcel-Laurin.
Do they offer 4 hours rate? I don't know.
Other than these? Well i don't think so.