Question trip to France

Can you fly from Dublin to Lyon instead? Aer Lingus (Ireland’s flagship carrier) has a nonstop flight < $100.
If you do fly into Lyon, you can take a direct train from Lyon’s Part Dieu Gare Routière station to Annecy (2h) or you can take a direct bus from Lyon’s Gare Routière Perrache station to Chamonix (4h). Transportation between Annecy and Chamonix is best by direct bus (1h 45m) so a day trip to either town is quite doable.
If you must fly into Paris, you can take a direct train from the CDG airport to Lyon’s Part Dieu station (2h). You then need to change stations that you can walk to or take a taxi. If you’re not departing from CDG airport there is a direct train from the Paris Gare de Lyon station to Annecy (3h 45m). There are no direct trains from Paris to Chamonix but there is a direct bus (8h 15m).

Thank you.
We do the Paris leg first, so we'd be leaving from Paris to Chamonix. (that's locked in)
Is it too much to stay in Annecy the entire time and just do a day trip to Mont Blanc? My husband loves hiking. Not sure if hiking is even doable in early May, but we'll definitely do a tram ride.
anything else you'd recommend while we're near mont blanc?
I want to minimize the travel time back to Paris, so leaving from Annecy by train to Gare de Lyon is faster than leaving from Chamonix and it might be a more quaint stay.

I'm worried about not getting on the train from GDL to CDG as they say it's often packed and we don't have a lot of time and will have luggage; are taxis outrageously expensive?

The "Gare Routière" mentioned just above means bus station in French.

I can see taking the bus from the bus station but for the train you'll need the train station. I haven't looked up either the bus or train schedules, but Lyon has two main train stations, Lyon Part Dieu (the main main one) and Gare de Lyon Perrache.

Happy hiking and sightseeing.

I’ve never been to Mont Blanc but what I do know about this area is what I’ve read in Rick Steves FR guidebook that I no longer have. Here’s what I found on his website: https://www.ricksteves.com/europe/france/chamonix then click on the + sign to the right of At a Glance. It sounds like you should skip Chamonix because to experience all that it has to offer requires five nights. As Rick says assume that you will return.

My opinion as a former resident of Lyon and now of Normandie, and someone who has visited both Annecy and Chamonix several times?
That would be to stay in Chamonix and visit Annecy, only if time allows,
Chamonix and its surrounding area are far more interesting than Annecy, unless one is unfamiliar with France and doesn't realize that Annecy (beyond its canals) is not particularly distinctive among French towns.

I think you should stay in Chamonix. Going up to the Aiguille du Midi (lookout point for unforgettable view of Mont Blanc) is best done in the morning before the clouds come in. You couldn't do that if you were staying in Annecy. Also, agree with other poster that it's sweet but there's not much to see in Annecy.

Do you just want to lay eyes on Mont Blanc (which you can do from a car without even stopping) or do you want to do any outdoor activities or other excursions while you are there? 1.5 days is not much time, especially considering it's not particularly quick to get there. Are you spending one night and leaving to go somewhere else, which is really only part of two days? Annecy is a nice place with a lovely lake to stop for lunch on the way but there aren't many sites to see. If you're just checking boxes, you can do both but you won't get to see anything other than the lake and the mountain.

ahhhh....I am a big fan of Annecy, simply because I love the ambiance, the food...think cheese...and the lake. I believe with such a short time you will be pleased with either, they are both beautiful. Annecy to us afforded bike rides, a boat ride on the lake, lovely market shopping, and just the most beautiful scenery for "just being", but, I could also say the same, but with different activities, for Chamonix. I have not lived in France-altho a frequent visitor-and would perhaps consider those that do live there. But....Annecy....just a fan!

You might enjoy a short you tube video by Wanderlust Travellers....drive from Chamonix to Annecy...just give you a good idea of what beauty to expect!

Rick hikes around Mont Blanc in his latest batch of French shows.