And we can also add the visit of 2 gorgeous chateaux like Villandry:

Me at Villandry

That's the best way to do it! (even though the one-day version also totally works).

The idea, if we do it in two days, is that we will only have one long drive per day instead of two. And, at the end of Day 1, we can spend at least one night in a small chateau (I'll give you amazing options and you'll make the booking according to your wishes). And then we have time for a gastronomical meal (preferably dinner to save time during the day) at an excellent price/value. And, during the next day, we can include a wine tasting:

Loire Valley in 3 days!

and Azay-le-rideau:

If I were you, I'd totally choose the 2-day version... or, wait a minute, here's even better:

If you add one more day (please do!), on the third day, we can visit the Chateau of Valencay:

We can have another wine tasting (the third one to keep the pace) at Sancerre:

And, most important of all, we will visit the Bourges cathedral (which comes second in my heart after the Chartres Cathedral) which I don't visit as often as I'd like to because it's a bit far away from Paris (130 miles) and it's therefore difficult to include it in a one or two-days excursion and this is such a shame (just to keep you informed).

Then we'll inevitably have a 2h30 drive back to Paris, but my little finger tells me that you'll need time to digest all this and that you'll love to just look outside the window, look at the sceneries and just savour the fact that you're there (well, that's the idea anyway!).