The trains in Spain...Tarjeta Dorado Question

Looking at the itinerary for our trip to Spain, it looks like most of our train travel will be on Mon-Thurs. Since we are qualifying old farts, it appears we can buy TD tickets. Looking at prices, the TD prices are all in shooting distance and sometimes cheaper than P prices.

I would like to keep the flexibility that the TD tickets allow. But, since we can't purchase a TD card until our arrival, my question is what is the likelihood of trains filling up??? It looks like the r/t from Madrid to Toledo itself will offset the price of the card. In addition, we are planning train trips from MAd to Córdoba, Córdoba to Seville, a day r/t to Jerez de Frontera ( and perhaps Cadiz) from Seville and a trip from Seville back to MAD.

Will waiting to buy the TD card and buying tickets once in Spain work out ok?

One of the key benefits of using the TD is the fact that one can still get a substantial discount at the last minute.

While some trains will fill up, frequencies are so great that I can not imagine you having a problem unless there is a special event or if you are traveling on a holiday period. If you are purchasing tickets the day prior you should especially be fine.

On some trains you may find you can get even better fares online even at the last minute though.

On popular AVE routes and times, they will even put in extra trains at the same time if the one train is completely sold out.