I once took my kids to Niagara Falls by train from Penn Station. It was in August and Chabad was open and serving food. We stayed in the Sheraton Four Seasons Hotel right across the street. The train took a ridiculously long time, particularly at the border stop (like 10 hours there and 15 on return with delays). However, we had a great time and it was very memorable. As crazy as the ride was, my kids still talk about it almost 10 years later. I don't know if the food options are available now and it is probably very cold. The frozen falls are still very beautiful, but I don't think you can take a boat on them. However, you might want to consider that for the summer.