I would say that smoking is allowed in the courtyard and outside the front entrance but others may know more.
A bit of history: the Hotel MacDonald is one of the oldest hotels in Edmonton. It was finished in 1915 as a railway hotel for the Grand Trunk Pacific and was one of the more impressive sights back in the early days of a small rural city. Along the way, someone had the "bright" idea of adding an ugly box addition to the south side, which drew the comparison of "the MacDonald Hotel and the box it came in". The hotel fell into some disrepair, and was closed for a while, until the addition was torn down and a major upgrade was done to bring its former glory back.
There's a set of stairs leading to river valley on the west side of the hotel. While that doesn't sound like much, the original stairwell was built over a hundred years ago. They were built so that passengers on the Edmonton, Yukon and Pacific railway could access the train from downtown, which ran through the river valley. The line itself was only a few miles long, going from the west side of the old downtown rail yards, into the river valley, across one span of the Low Level Bridge (visible to the east of the hotel), then north through Mill Creek Ravine and connecting to the Canadian Pacific Railways line about 3.5 miles away. The rails were torn up years ago but the history is still there.
Thanks for taking the tour and have a pleasant day.