We will be traveling from Rome FCO to the Cinque Terre on a Saturday noonish, by train. Would Eurostar straight thru to Pisa be best? Other? Do we get off at La Spezia? We will be staying in Portovenere
Joy, There's a direct train (no changes) from Roma Termini to La Spezia, with a travel time of ~3H:45M. That would be your best option for getting to that area. In checking the Trenitalia website, the closest to noon is a train departing Rome at 12:10, arriving La Spezia at 15:51 (reservations compulsory). You'll have to use Bus or Boat from La Spezia to Portovenere. Happy travels!
Grazie!