I guess it depends on the definition of "quaint"!

Personally, I would NOT consider Sevilla, Granada, Cordoba, or Ronda "quaint"-- although I thought them all worth seeing.

Well if it’s going to be Holy Week in Barcelona it will be the same in Sevilla ie very busy and very expensive and very booked up. Not so quaint at that time of year. So keep that in mind when deciding where to go.

During la SS Seville is a madhouse...it is rather busy in Adalusia period. Many Spaniards trave at that time.
If you are looking for quaint ( in a good way) , take a train to Madrid and continue to Toledo.
But it could be rainy and cool in March in that part of Spain.

Toledo is quaint if any place is IME. But you have such limited time - I'd do it as a day trip from Madrid and also spend a few days in Madrid - one less relocation saves a lot of time. I would not go to Toledo and not Madrid (though many here seem rather nonplussed about Madrid but it has some if not quaint areas really nice ones like Plaza Mayor and Royal Palace areas and of course world-famous museums like Prado -n also nice area with nice park.