Boutique Hotels in Paris

Not in Le Marais but we are staying here at the end of September. I can report back if you’re interested!
https://www.google.com/maps/place/H%C3%B4tel+Ad%C3%A8le+%26+Jules/@48.8646801,2.3279363,13.59z/data=!4m18!1m8!3m7!1s0x47e66e03cdce4ae9:0x38cfa580446f9e46!2sLe+Marais,+Paris,+France!3b1!8m2!3d48.8612327!4d2.3581892!16zL20vMDFzeWo0!3m8!1s0x47e66e3e1a155b0d:0x86112e1cf403e2f!5m2!4m1!1i2!8m2!3d48.8721821!4d2.3452536!16s%2Fg%2F11clgn7x04?entry=ttu

Up US$300 for a room for one or for a double room. I'm not sure about the February 2024 but I have two suggestions that I really like in Les Marais: Hotel Les Tournelles and Hotel Caron and please note that this is Hotel Caron not Hotel Caron de Beaumarchais which many love but whose decor is IMO too old fashioned for modern life.

I love this hotel. It is near the Marais & City Hall. Look at Hotel Britannique. It is very charming. It may strain your budget, but Paris hotels are super expensive right now.

I was also going to suggest Hotel Britannique, which is not in the Marais, but central and charming.
https://hotel-britannique.fr/fr/page/photos-hotel-britannique.15674.html

You don't say how long you'll be staying in Paris, but perhaps you might consider an apartment if longer than a few days. Check Guest Apartment Services - shoot them an email for what is available for your dates - they're reputable and great to work with. They have many properties in the Marais.
https://www.guestapartment.com/

Thank you all for your suggestions. I will check them out. For the first jaunt because it will be February and basically a French Seattle, we'll spend about a week in Paris, then head south for warmer weather, visit a nephew. Probably return around the beginning of March to settle into an apartment for about 2 months with day trips or overnighters on occasion. I also saw an apartment for a week, so still in the investigation stage. The planning evolves.

@wmags11 I'd love to get your opinion of where your staying in September.