Paris & Chartes; Hot chocolate;

Were you thinking of Angelinas on rue de Rivoli for your hot chocolate?

When is your trip? Monet's gardens will close Oct 31.

I am not sure that it is possible to do your item 2 in one day.. Your hotel is just across the border from Paris. Have you looked at the RATP website or the Transilien website to see how long it will take to get from Clichy to Vernon and then from Vernon to Chartres? That is probably 6 hours of just travel time. Plus, I am not sure that there is a train back to Paris from Chartres that will allow for a romantic dinner in Chartres.
Le Train Bleu is a restaurant at Gare de Lyon. You may find it romantic.

Giverny and Chartes in the same day seems impossible.

"We wish to visit, via train, Monet garden (Giverny) , morning, then , in Afternoon & evening via train to , Chartes"

Honestly, I don't think this is a good idea as I think you will have to return to Paris, change train stations and then head for Chartres. For myself visiting Giverny takes at least half a day plus train/shuttle time to/from so at least 3/4 of a day. Chartres takes the same time for me and you'd want to be there in the daytime when the sun is shining on the stained glass.

To me with just 3 days in Paris, I think 2 day trips is too much. I'd not even really want to do one but if that works for your style of travel (instead of my style of travel, lol!!) then choose one or the other. Both are worthy. As mentioned, Giverny will depend on when you are traveling.

If you're there when the light show is on in Chartres, you should spend the night there.

My niece and I had thick hot chocolate at Carette, near the Trocadero metro stop (there are other outposts, do a google search). It was pretty good and I'm not a chocolate person. You likely will have to stand in line but it goes pretty quickly. (it is not inexpensive, btw)

I've heard that the hot chocolate at La Jacobine in the 6th arrondissement is very good and is quite thick. I would avoid Angelinas. The setting is good but the wait can be terrible and it's a tourist mill. Only go if you want to go because you have heard so much about it but prepare to be disappointed.

I agree with all the warnings about not being able to do a trip to Giverny and then Chartres in same day. I also agree that getting chocolate at Angelina's may not be worth the long wait, or the fact that they squeeze you into small table which is only inches away from guests at nearby tables. But the decor at Angelina's is nice, if you are into art deco. But you could get a drink at Le Train Bleu, which has really amazing decor, and I think would put Angelina's to shame if they were put side by side. I do not know if le Train Bleu has hot chocolate worth recommending.

For Chartres if you are staying overnight which you should (the last train to Paris to pretty early). but if you have time for dinner, our go to is https://restaurant-moulin-ponceau.fr/fr/. which sits right on the little river below the Cathedral with some tables in a glassed in area right on the river -- lovely views of birds, flowers, river. We ate there about 25 years ago and then it was closed and last year we spent the night to see the illuminations and had dinner there. Superb food, service and views. I think that are open Weds through Sunday.

I echo Janet's choice for a romantic meal. It doesn't get any better in Chartres.

Is there a reason you're going with that hotel in Paris? The location is not in Paris proper, but in Clichy. You'll be spending a lot of time on the metro. There's another Voco near Montparnasse if you're dead-set on a Voco.

For hot chocolate, I find Laduree has great hot chocolate. La Jacobine has become an American sensation because of the Frenchies youtube page. I also like Angelina-- yes, it's a tourist mill but most of these places have become one. It is delicious and there are a few locations to choose from. I go to Laduree rather often as there's one not far from my quartier in Beaugrenelle.

Please... skip Angelina's it's not "thick" and IMHO the hot chocolate I had at a random cafe was DRAMATICALLY better and didn't come with rushed service (all that's missing is a cattle prod to get you moving out the door faster LOL!) . Angelina's has just become a tourist trap IMHO. (Here's your sign in Paris, if you and hundreds of other American's are standing in line... RUN!)