I flew through CDG 2 days ago. I had to transfer from 2A to 2E on the bus. I had pretty much "perfect" transfer conditions - no queue at security, done it before and had some clue what I was doing, bus was waiting when I got to the bus area and pulled out immediately. It took a GOOD 40 mins to just transfer between the terminals under these conditions, with no luggage to collect. With any minor conditions that are less than perfect, an hour easily. Add luggage issues into the mix, and I would leave 2-3 hours.