Moving around Paris during TdF final stage

[Claudia]

I'm in France atm - just by the intermediate sprint zone of today's stage - and will be going down to Paris on Sunday, early in the morning, dispatch the bikes back to London from gare du Nord and our return Eurostar train leaves at 8.45pm.
My boyfriend just won't go back to London without seeing, at least, 1 lap once the riders get to Les Champs Elysees. How easy is it to get to any local train station given we won't be there until the end of the whole thing? Are metro stations normally open? I read some weren't but this was 3 years ago...

 

[Globalti]

We watched it in the Champs Elysées last year and weren't aware of any stations being closed. Obviously the Metro will be chokka as soon as the race finishes but if you leave early you'll only be bothered by the stink of urine in the tunnels.