The departure time and location of YUL means that in any case you are better eating in Montréal. Though the third party lounge in YUL isn't great by comparison with LHR, with very limited food options in particular, I don't think it's quite up there with RAK or ALA, it's fine for a drink or two before departure. What is difficult to avoid is that it is too short for an overnight service. Because YUL doesn't suffer from the congestion of BOS or YYZ, the flight can be incredibly short. That's a geographical fact of life to which there aren't any easy answers. It would be great as a day time return, but the economics won't work for this from LHR-YUL.