The views here are equally polar, but your govt's work is making headway, I believe. Search on the word "basecalc," or go directly to the source: http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/eng/software_tools/basecalc.html Best you try it on a computer running Windows XP

Here is the short course: foundation walls are the source of most basement heat loss, and much of that happens above ground. You have that source well covered by ICF's double foam, and placing a skirt on the lower grade is money well spent. You'll want to place xps between the slab and the top of the footers. You may want to extend this thermal break by running foam around the perimeter of the slab for the first meter, leaving the center uninsulated. But Canmet's "Performance Guidelines for Basement Envelope Systems and Materials" http://irc.nrc-cnrc.gc.ca/pubs/rr/rr199/rr199.pdf deals with underslab insulation in a single word: "Optional"

The story changes if you are putting radiant in the slab, or the water table or bedrock is close to the surface. The model has a climate and soil profile for Saskatoon. You might want to ask an engineer type if the defaults are realistic.