Could I check in at CDG and spend the night hours at the CDG airport leading up to my flight?

Can't check in until roughly 3 or 4 hours before your flight and the ticketing area will be open but not much there. 

The problem in most European airports is that they don't have a check in desk until about 3 hours before the flight. If you haven't checked in, you can't go through security, and the facilities outside security are very limited. I once got stuck sitting on a concrete ledge for 4 hours because of that. Spend the money for a hotel. There are a number of reasonable ones with a free shuttle from and to the airport.

YOU COULD. It will not be very comfortable for you but is possible to do.

The Airline probably will not accept your luggage until a few hours before departure.

Leave your luggage at a luggage service or drag it around with you.

The Paris Charles de Gaulle Airport is open 24-hours, but if you haven’t gone through Security before the checkpoints close for the night, around 11:00 PM or later, you will have to stay in the check-in or arrivals pre-Security.

The Airport is known to be chilly at night. Have something for warmth.

i dont see why not, ive gotten stuck spending the night at the airport before

Get through Security early - before 11 p.m. Paris Charles de Gaulle Airport offers one or more designated rest zones with semi-reclined lounge chairs, perfect for relaxing and napping before your flight. At least one such rest zone is at the far end of Terminal 2E, near Gate K30.

Stay at the Ibis CDG. It's a lot more comfortable.

https://www.accorhotels.com/gb/hotel-8231-ibis-sty...