went two years ago with a Phil and Teds and it was a bloody nightmare. Had trouble getting on and off some of the trains as the doors were not wide enough and we didn't realise at first that there were only certain doors that could be accessed with wheelchairs and pushchairs. Hopefully it has changed by now. Maybe look out for Bonsoir or send her a pm. Am sure she lives in Paris and will have much more up to date info than me. Try posting on 'living overseas'. I hope you manage your trip ok.
Metro tricky as not many stations have lifts. . Buses also not all wheelchair friendly - am not sure they have bit where can put wheelchairs and certainly not sure they have the lowering thing to help chairs get on
I agree; I think the metro is out. very few stations are pushchair accessible. We passed through Paris in the summer and I has DD2 on a hippychick to avoid the lift problem. We climbed miles of stairs..... Sorry that's not reassuring!