Enough risk at the G7 palavar in ‘Kananaskis Village’ west of Calgary AB mid-June this year. Aerial exclusion area seems small given speed of some business aircraft. Conferences usually held in hotel there, not ‘glamping’ in the bush, so attendees are easy to target.
Having a CF-18 airborne 24/7 would be costly. Ground-based missile defense needed. (Perhaps Ukraine could spare a couple of its aicraft-downing UAVs. 
(Security will be tight, pre-clearance required to live or do business near the village.
It was evident for the last big conference, I observed driving from Edmonton past the area on Highway 1. US Army driving south from Edmonton, Springbank airport occupied, clean cut males in new 4bys lounging on banks beside the freeway,)