My husband and I did the river cruise from Montreal to Quebec City and opted to have an overnight stay at the Chateau Frontenac and return the next afternoon by bus to Montreal. The only downside with the cruise is that the boat departs at 7am and you are asked to be there about 6am, so that is definitely an early morning.
The boat travels at the speed of a bicycle (that is what the captain told us) so it took about 9 hours to make the trip to Quebec City. They provide you with a delicious breakfast and lunch and there was a variety of activities to occupy your time during the morning and afternoon. Live music, dancing, chart navigation, wine tasting and board games were some of the pasttimes folks were able to engage in as the voyage went on.
Sadly, it was a rainy and overcast day so we missed out on sightseeing along parts of the St. Laurence as the shore was just to foggy to see much of.
The gentleman doing the narration during parts of the voyage was very friendly, helpful and entertaining! We enjoyed our trip and found that everything was well organized and arranged. There were no issues with our arrival at the hotel or departure the next day (all of which was arranged by the cruise line during our reservation with them).
If you are looking for a relaxing day and don't mind being on a boat for 9 hours, I would definitely recommend this trip and this company!