I thought your plan to take the RER was ok, till you mentioned lots of luggage,, Chatelet has LONG long passageways ,,lots of walking,possibilities of stairs, escaltors sometimes broken,so how much luggage is "lots"( I advise you to take less, no matter how long your is)

I would be nervous with bus option, they usually take alot longer ,, how early does bus leave?

Two hours is about right time, I think I have gone 1.5 hours ahead for inter europeon flights and been ok, but with security it does make sense to allow 2 hours ,,, sometimes you hit it unlucky and end up waiting alot longer to get through security then you had planned. Also you have to allow time to get to terminal if you take bus,, and CDG is large, spread out, and for many if not most of us , confusing.

Should say this,, I personally would take a taxi,, you've spent thousands on this trip,, this may not be the best time to economize,, have a sandwich for lunch on a park bench for two days instead of lunch at a restaurant,, that will make up for this little extra expendature, and save you alot of stress.

Lots of luggage = take a taxi.

Hahaha....had a feeling people might say this. I don't know if a lot is the right word...two medium sized bag, one rolling carry-on, and a backpack. We've trekked all over Europe with these bags, and I've been in and out of the stations over the past months so I have a sense of what' s involved. Though the bus might be easier but can't find much about it so possibly not the time to be trying that out.
If we go the metro/RER route, I think we should leave an hour and a half for all of it, yeah?

oh and apparently the bus leaves as early as 5:30 am.

We've taken the bus on the hottest day of the year when Paris had its terrible heat wave--I think that the temperature reached 40C. It is a long ride and requires an extra ticket or two. Check if the RATP web site will give you an actual schedule for the bus.

Thanks Michael. I did see that it would cost three tickets. I found a schedule but its different on saturdays, different in the mornings, so I'm still trying to sort it out. Do you remember how long it took you?

Now that I think about it, I'm not even sure the metro or bus run early enough...

This is tomorrow. YOu have 4 bags between you--two of them full handfuls. As you say, you've been there done that.
Seems easiest to take a taxi and chalk it up to realistic travel expense. JMO.