Taxi from Paris to CDG

When you check in, you might ask your hotel to arrange transport for you. Private shuttle will cost around 50 euros from that area.

I think the 50 euro estimate may be a little low for a hotel arranged car but accurate for a taxi. We had an early flight and took a car arranged by the hotel. We were at the airport in 25 minutes since there was no traffic and the driver clearly thought speed limits were for other people. I think I would try a pre-arranged taxi in the future. Either way, your hotel can arrange and no reason to worry too much in advance.

Agree with having the hotel arrange a private shuttle or taxi. Have never had a problem with that solution in Paris.

We've had our hotel set up a taxi for early morning to CDG and it worked well, 50 euros is in the ballpark, might be a little more from your Left-Bank location, and bags are extra. Plus you may pay for the taxi to come to your hotel from wherever it started. Taxis are generally reliable when called in advance by hotels for specific times, even that early in the morning. You don't really have an alternative that early, except for staying at the airport the night before. (That's what I would do if this were my trip.)

Normally the advice is to get to the airport three hours before an international flight, i.e. 4:30 AM, which means the taxi at maybe 3:30 to be on the safe side. The question is how early your airline will be staffed to check you in. Our last flight home was around 10:00 AM and we were in an airport hotel, so got to the terminal quite early, around 5:30 as I recall, and Air France/Delta wasn't open. We waited awhile with other sleepy passengers for their check-in to open for us. You may not have that problem with a 7:30 flight, but it might be worth checking with the airline to see what time they'll be ready to check you in at the airport. No point getting there three hours ahead and standing around waiting for them to staff up.

If you do decide to stay at the airport that night, we found the Ibis to be comfortable and convenient, though not luxurious. Stay at the airport itself, not in nearby Roissy, for such an early flight.

Did the airline offer you any options for another later flight? Whenever the various airlines that we have flown have notified us of a change of this magnitude and leaving the early, they have always included a question asking it this change is agreeable or causes any unsurmountable problems. I stayed in Paris twice this June/July. The last time we went to the airport and stayed at the airport Ibis our last night rather than having to deal with a situation like you are faced with. Hope you are able to work things out.

To the OP:
I'm guessing your hotel is actually the Hotel du Champ de Mars (as in, Field of War, near the old military academy and Tour Eiffel).
Sometimes spelling will help, such as in what name you give a taxi driver, etc.

Ouch. LOL Yes, the hotel is Hotel du Champ de Mars. I will make sure I give them the right hotel. ;-) Thanks for the tip.

You can also make Taxi arrangements yourself ahead of time through G7 Taxis, http://www.taxisg7.com/taxis/commande-taxis, they have English speaking personnel. They also have an App you can download and book from your smart phone. Also, Uber-X,https://www.uber.com/cities/paris, the government approved Uber service in Paris.
Enjoy your trip.

We had the same situation and were in relatively the same area...as brushtim suggested, we called TaxisG7 ahead of time and had them show up around 4:30-5:00am...because it was so early, there was no traffic and we were there in about 25 minutes....no issues whatsoever.

You can also just book online with TaxisG7, which is what I did. They were on time and no worries. But I also knew where all the Taxis lined about a 5 min walk from our apartment, so I figured if they did not show up, I had a plan "B".

ladd - we too had a flight change and I was most disgruntled to be stuck with an 8:00 a.m. flight home from Paris. The hotel arranged a taxi for 5:00a.m. The cost was 70e for the trip. Traffic was sparse at that hour and we made it to the airport with plenty of time to spare. The airport was mostly empty and very easy to navigate at that hour. Leaving early may have been a big plus for us. The Rue Cler area is lovely and if you walk down Rue Cler itself there is a lovely donut shop on the right about halfway down the street.

As a follow-up to my original concern about getting to the airport for an 8 AM flight, everything turned out well. The folks at Hotel du Champ de Mars arranged a taxi for 4:30 AM. We didn't have any issues. The traffic was light, and we got to the airport in 45 minutes. Our taxi driver thought he was flying a rocket. The cost (70 euros) was a little higher than told. As an extra bonus, the airport was very quiet. As a matter of fact, we waited for American Airlines to open their doors. BTW My flight was on a Tuesday. Overall, it was a pleasant experience. I would like to thank everyone for their shared experiences and suggestions. Happy travels!