When researching places to visit in Quebec, I find it useful to compare how convenient each destination will be for the whole day, not just the main activity.
Casino Lac Leamy can be included in a shortlist of entertainment venues around Gatineau, subject to checking the latest official details. Transport, nearby accommodation and dining plans are all worth considering before travelling. I would also confirm any current age restrictions, entry conditions or other visitor policies rather than relying on old information. If gambling is part of the outing, it should be treated as entertainment with a clear budget, since no game or strategy can guarantee a win.