Avignon to Avignon TGV

I think my Plan B is to take a taxi, and my Plan C is to take the next train from Avignon to Paris (one hour later).

Your plan C is a better plan B.

Michael, you may already have purchased tickets so this question may be moot but are you aware that the Avignon -Paris TGV operates out of both the Avignon TGV station and the Avignon Gare Centre (Locagest)? You should be able to book an Avignon Gare Centre-Paris ticket unless your timing doesn't work out for it.

Really? When I went through all the ticket options, they all seemed to indicate that it was out of the Avignon TGV station. I am going to Paris CDG, maybe that makes a difference?

The answer is "yes." According to the RailEurope website, trains to Paris Gare Lyon operate out of both Avignon train stations while those traveling to Paris CDG only operate out of the Avignon TGV station.