Banff is the easiest landscape in Canada to photograph and one of the harder places to run a wedding in, and both facts have the same cause: everybody else wants to be there too. Moraine Lake is shuttle access only, private vehicles are not getting you or your guests to that shoreline, and the good hour at Lake Louise is the one before the coaches arrive. A photographer who has not worked there finds this out on your morning.
A ceremony on Parks Canada land needs a permit, and the process is slow, seasonal and capped by site. It is the single most common reason a Rockies plan falls apart in the final month. I arrange it rather than hoping nobody asks, which means I need your site months out rather than weeks.
What you get in return is scale nothing else in the country matches. Glacier-fed water that reads turquoise without a slider being moved, larches turning gold for two weeks in late September, and mountains close enough to fill the frame behind two people standing still. Put a wedding party in front of them and they do not get any smaller.