*Agree with St. Chappelle. On a free wandering day, we impulsively decided to stand in line for sans billets- without tickets-- and waited 2 1/2 hours from 2:45pm to 5pm and was let in. It was TOTALLY worth the wait according to young adult daughter. (Of course she has no memory of having seen it previously and acting bored at 10yo.Sigh).
. After 4:30pm (close at 7pm) line guard were telling people they're very unlikely to get in today and their chance is best when it opens at 9 in morning. (There was no more online tickets).
While in line I read in RS we could try to buy combined tickets to Concierge and St Chappelle. We would have been able to get in the much much faster -tickets without timed entry-- but I didn't want to risk getting out of line in case.
FYI about journey to Giverny. I made a mistake and got on the slow 7:47 train to Vernon-Giverny instead of the 8:14 am Faster train, so our journey was 80 minutes instead. We ended up arriving about same time as original train because that one was delayed, and we had seats.
We thought we would take taxi to Giverney for ease but couldn't find one. We'd missed the shuttle but a very touristy and fun small shuttle "tram" was outside. Buy just one way, not return because tram runs every 2 hours back to train instead of every hour shuttle does. Tram was right outside of train station--hard to miss.
For the shuttle from Vernon Train to Giverny and back , the driver gave me a brochure in English to let me know what time it goes back to train station... this was incredibly helpful since I wasn't sure how long we would stay at Giverny. Playing by ear we did.
FYI, shuttle leaves (from same spot where it drops you off at Giverny Parking ) 20 minutes after hour (except 11am and 3:10 pm) , about 10 minutes or so before train back to Paris leave. (Small station, so that's plenty of time)
shuttle website is sngo.fr (don't know how to link on mobile).