Hi Julie,
Illuminations: Reflections of Earth is one of my favorite nighttime shows in the theme parks. The dynamic music, narration, and lazer/fireworks are spectacular. So, I know you won't want to miss it.
I will say that watching it from Chefs de France is possible. However, your views will be quite obstructed by the guests viewing it from the fences that surround the World Showcase Lagoon as well as trees outside the restaurant. My husband and I did view it from a window table that we lucked out on getting one evening at
Monsieur Paul, the upstairs restaurant in France. But, again, views of the entire production were more obstructed and there are only a few tables with this view, but I feel we got a slightly better view over the guests since we were upstairs.
In my opinion, I would try to get an earlier dinner reservation at
Chefs de France and then go out to see Illuminations: Refections of Earth after dinner. The show typically begins nightly at 9pm, so I would recommend trying for a reservation around 7pm to allow time to eat and still have enough time to get a good spot around World Showcase to view it.
Have an amazing evening at Epcot!
~Allison L