For the Victoria Day Weekend in Western Ab you could have temperatures approaching 30C or you could have 0C with 1 or 2 feet of fresh snow.
If it is at all nice it will be the busiest and rowdiest of our long weekends. Most decent sized campgrounds work hard to keep control but it has been a long winter so expect some noise particularly in smaller unserviced areas.
If the weather is ugly there will be sites but an electrical outlet would probably be appreciated.
Either way a reserved serviced site in the National Parks would seem like the best alternative to me.