Just did a calculation of Red Deer's future metropolitan area with the 2016 Federal Census numbers, this includes:
City of Red Deer - 100 418
Red Deer County - 19 541
Town of Sylvan Lake - 14 816
City of Lacombe - 13 057
Lacombe County - 10 343
Town of Blackfalds - 9 328
Town of Innisfail - 7 847
Town of Penhold - 3 277
Town of Bowden - 1 240
Town of Eckville - 1 125
Town of Bentley - 1 078
Village of Delburne - 892
Village of Alix - 734
Village of Clive - 715
Village of Elnora - 298
For a total of - 181 709 people across an exorbitant 6727 km2, which would make it the 7th largest CMA/CA in the country by area, 23rd largest in population, larger than Abbotsford. The CMA would have a population density of 27/km2, comparable to Kamloops (17.4/km2), and Lethbridge (39.5/km2) and other cities with large hinterlands/catchment areas.
Did the same calculation for Grande Prairie's future metropolitan area, this includes:
City of Grande Prairie - 68 556
Grande Prairie County - 22 303
Town of Sexsmith - 2 620
Town of Beaverlodge - 2 465
Town of Wembley - 1 516
Village of Hythe - 827
For a total of - 98 278 with around 14% growth since 2011. The area is 5 802 km2 for a population density of 17/km2.
Did population projections to 2031 for the 7 largest CMA/CAs in the province as well, assuming Foothills joins the Calgary CMA, Red Deer acquires Lacombe and Red Deer Counties, and Grande Prairie acquires Grande Prairie County:
Calgary - 1 464 000 - 1 970 000 (2%/year)
Edmonton - 1 321 000 - 1 778 000 (2%/year)
Red Deer - 182 000 - 245 000 (2%/year)
Lethbridge - 117 000 - 157 000 (2%/year)
Grande Prairie - 98 000 - 142 000 (2.5%/year)
Fort McMurray - 73 000 - 91 000 (1.5%/year)
Medicine Hat - 77 000 - 89 000 (1%/year)
All of these growth rates are significantly less than our current 15-year average, so this is more of a medium projection scenario.