Phew! What a chaotic morning!
We arrived at our nearby Ste. Placide Metro station at 10am ready for the straight shot to the Gare d’Est SNCF station and were met with a closed gate. It turned out our local line is closed on Sundays for construction!
Google Maps to the rescue again! It gave us a route that accommodated the multiple line closures on Sundays. We hauled our baggage through the streets of Paris to another station about 500′ away, took the green line a few stops, then exited one station and went to another that was another 500′ away to get to where we needed to go.
If it weren’t for our train having a 20 minute delay — which we knew about earlier this morning — we’d have missed our train! But here we are!