I would prefer to stay above ground and see the countryside.Best regards, David
I can't find either your hotel name "Hotel George Opera" nor that address in Paris "45 rue Notre Dame". Can you provide some more details on where you're starting your journey?
The route with the least amount of walking would be RER B from CDG to Paris Gare du Nord, transferring to RER E direction Haussmann-Saint-Lazare until the terminus, transferring to Metro line 12 direction Front Populaire until Saint-Georges station and walking from there. All transfers can be done using the original RER ticket.
The RER B will be mostly above ground until close to Gare du Nord where it will go underground.