Snow: Since the CSM course gets groomed at the last minute it won't be as hard as the parkways, but it could be more abbrassive since the older snow underneath gets churned into the top layer during grooming.
Forecast: -17C overnight Friday, +3C Saturday as a high with 60% chance of rain or snow most of the day and overnight staying above 0C and falling slowly Sunday morning.
Glide: The easy one first. No need to be fancy. A couple of layers of green base followed by a violet top coat will work well. Fluoros will keep your skis clean longer and glide better if it warms up. You might consider carrying a wipe-on glider for Saturday afternoon and Sunday.
Grip: Hmm... waxless skis, hairies? It's going to get interesting out there.
Saturday AM - Binder is necessarry, you are going a long way! My choice is Vauhti Superbinder. Iron in a thin layer, cork smooth and let cool. Then add a thin layers of cold Teho green and cover with Carrot (orange). The Teho gives you some added temperature range to the grip. If your really lucky that might work all day.
Now, sometime Saturday its going to warm up fast. They predicted something similar last weekend, but it happened much latter in the day. So I hope that repeats and you are finished by the time that front rolls in because it looks like it might be accompagnied by snow and rain. If that happens you will likely need to progress to a stickier wax as the snow/rain transforms the tracks. The binder+Teho+carrot will work even with fresh falling snow, but once the tracks glaze or there's rain you need purple/red/aluminum. (I like Aluminum for glazing and mixed conditions.)
I'd suggest having a rainbow of waxes with you - green, orange, purple, red and an aluminum, as well as a universal klister in your fanny pack. I've also had great sucess with the Vauhti Silver Plus and Silver Minus klisters. The Silver Minus Fluoro being very good in mixed conditions around 0C. A putty knife to clean off old wax, can fix a lot of mistakes fast and is worth carrying too. Don't end up with 20 layers and skis that drag, you don't want to be out in the rain too long!
If you find yourself starting to slip don't add thick layers or wax aggressively! Stick to adding thin layers, 2 at a time. Use a cork and keep it smooth.
For Sunday morning keep these combinations in mind around zero. If there's been lots of rain, universal klister will likely work but try kick-wax first.
But remember this is "virtual" advice I haven't seen the actual tracks or snow type. Remember to carry a couple of waxes with you; one warmer than you are using, one colder and the one you are using just in case. A putty knife is a good idea too!
Whatever wax you use, good luck and enjoy your big day! Oh, and should you care to share your adventure with us, send us an email and we'll post it here.