Just to update, my sister and her new husband did settle on a honeymoon spot. Despite my emailling and talking to them about other options out there, they ended up sticking to the original plan: a night at the Banff Springs Hotel (which they told me they enjoyed immensely), and now they are off to the Sunshine Coast in BC. They found a nice romantic lodge and they are spending until Sunday there. It happened to be the most affordable place out of the suggestions that they haven't already been to. The Pacific Ocean will, undoubtedly, be spectacular. Also, after an extremely cold wedding in Banff, they were ready for a milder climate. Thank you once again for your suggestions, though.