It's a very good reminder bearing in mind the present civil service industrial action in France. You can find ATC being withdrawn without expecting it.
Going into Agen last week we were told by the ATCC that there was no ATC at Agen - thankfully they gave us the phone number to call to close the plan but it was then down to the good old fashioned joining R/T calls in french to the local aeroclub - quite amusing considering we were in a Citation at the time!
On arrival we did find in the airfield office (manned by the fire staff) the relevant numbers to call - no doubt most airfields can supply them if necessary.