If I allocate one hour for a taxi ride to CDG from a hotel near Invalides at 6 a.m. on a Saturday morning, am I in the ballpark?
Well, it depends on the time of year probably, but I took a G7 taxi from our hotel in St. Germain to CDG this past Sunday morning (April 9) at 7 am, and we got there in about 25 minutes with very little traffic. So I would imagine leaving at 6 am from Invalides on a Saturday would get you there in about the same amount of time.
That shoiuld be ample time and you should reserve on the G7 line two days before. We have had cabs not be available when trying to reserve the night before and I don't like to leave it to the morning for something so high stkes