RER "B" or Air France Bus...

Here's a link to a map of the Air France bus stops at CDG: http://tinyurl.com/9l5y2fk The Air France buses can definitely be delayed by traffic conditions. It has happened to me. Here's a link to the RER "B" airport info: http://tinyurl.com/3a8zbpq The RER is highly unlikely to have any delay.

I know what I'd do that last night. I'd travel out to CDG and stay at the Ibis hotel at Terminal 3. That way you'll have no worries. I admit to being a bit paranoid about glitches that might arise with transportation to airports. For peace of mind, if I have flights before 11 AM or so I like to sleep near or at the airport.

I'm indebted...I wonder how difficult to get a taxi at 5:30 a.m. to take us 3/4 mile from St Marcel and Blvd Hopital?? (just west of Gare Austerlitz). Like is it chancey to get a cab, and will it cost an arm/leg for two folks w/carry-ons only, at that early hour on a weekday??

Rosalyn definitely has the answer, it's the same as we have done in the past. If you stay at the Ibis at terminal 3 you can get up at a reasonable hour, have a pleasnt breakfast, walk 200 feet to the station and take the free rail shuttle for the 5 minute ride to terminal 2 all toally worry free. There now, doesn't that sound easier than any of the alternatives you have raised? Catching a morning flight out of CDG is stressful enough, why make it ten times worse? I defintely would not take the bus.

Your hotel can reserve a taxi for you the night before.

With a 10 a.m. flight, you need to be there at 7 a.m., which means leaving at 6 a.m. You won't have much commuter traffic in the metro at 6 or the RER B going that direction. Rosalyn has an excellent idea, staying at the Ibis Terminal 3 the night before and roll out of bed into the terminal in the morning.

Be aware that the RER B line divides northeast of Paris so be sure to get on a train that is going to CDG. You don't need to walk or take a taxi to Port-Royal. You can take Metro line 5 from Saint-Marcel to Gare du Nord and transfer there to the RER B. Leave Saint-Marcel at 05:49 and arrive at CDG 2 TGV at 06:43. Or leave Saint-Marcel at 05:58 and arrive at CDG 2 TGV at 06:59.

Last month we had a 10:30 flight from CDG to Chicago. We departed our apartment near the Bastille at 7:00, walked the 6 blocks to the Bastille Metro stop, got on the Metro toward Gare du Nord at about 7:20. There, switched to the RER B at 7:30 and we were at CDG around 8:00. No problem. Rush hour isn't really an issue at all. However, to simplify things, we stopped by a Metro ticket counter the day before and bought our tickets ahead of time.

The point is,, there is no rush hour traffic at 6 am ,, most especially at 6 am going out of Paris! Where did you read that rush hour begins at 6,, ha, most shops and businesses don't even open till 9 or 10, and most people commute into Paris in the morning, not out of Paris, so the RER line going out is not going to be an issue.
If you take the RER out at 6 am you will be at airport by 635-645 .. lots of time.

lindley, Another option you could consider (if your budget allows) would be to stay at the Sheraton Paris Airport Hotel, which is built right into Terminal 2. That way you could simply walk from the Hotel to Terminal 2E, perhaps at 08:00 or so after you've had a good breakfast. With a 10:00 flight, that's an option I'd consider, even though the room prices will likely be in "posh" range. Cheers!