Sounds like an awesome trip. I cycled two thirds of the triangle back in 2006 (Junction #93 to Radium to Golden). Though I can't give you a more recent update on the roads, I recall that the #95 north to Golden had virtually no shoulder. But traffic was lighter.

Back in 2002, the campground was closed at Lake Louise when I cycled through because of an aggressive Grizzly. I stayed at the hostel there instead.

When do you plan on doing this ride? If there is some flexibility in your time frame, I would shoot for June. There will be less camper/rv traffic.