We are thinking of going to Montreal for Labor Day weekend. 3 nights with DD who will be 14 months at the time. We will probably do VRBO so we have more space, unless anyone knows of any great hotels that have babysitting or other child facilities.
We stayed at the Hyatt on Jeanne-Mance for our first trip and enjoyed it. We've gone back a few more times since then and we always stay at a B&B - Hotel Auberge de la Fontaine. I don't know if either facility has childcare services: www.aubergedelafontaine.com/montreal-hotel/#.VaP3F_lVhBc
Au Pied de Cochon would be great for a kid-free dinner. Book reservations ASAP.
La Banquise is an all-poutine restaurant and is open 24/7. Might be best for a kid-free snack or if one of you brings back takeout, though, as space is tight and it seems like a mostly college-aged crowd.
Walk around Old Montreal and look in the shops. Also walk around Atwater Market and Jean-Talon Market.
Dieu du Ciel is a great brewpub if you really like craft beer.