Unless you want to spend long hours pouring over the exceptional art treasures in Madrid’s museums, then I’d definitely plan a day to Toledo.
Temple of Debod
Plaza de Espana
Plaza de Oriente
Plaza Mayor (morning coffee)
Puerta del Sol
Plaza de Cibeles
Puerta del Alcala
Lunch in the Salamanca district before strolling thru Retiro Park.
Visit Basilica San Francisco el Grande, before exploring the historic La Latina district, with lunch on Plaza Santa Ana.
pm...Reina Sofia Museum
Ensure you get to Santa Cruz for its opening at 10am and you will get the most out of your day, time wise.
10:00 Santa Cruz Museum
11:30 Cristo de la Luz
12:15 Santo Tome
14:00 Synagogues (one or both depending on time!
15:30 Monastery San Juan de Los Reyes
16:30 Cathedral (closes 18:00)