We're staying in Garda for a week in early August and would like to visit one of the thermal park/pool at Cola or Sirmione. With limited time (a week) and a budget on our hands, we'll probably only have time to visit one as there is so much to do on the lake. Is it easy to get to Cola from Garda town by bus? We will also take a day trip to Sirmione by ferry at some stage. Would appreciate any tips on either of these thermal pools and if visiting one, which would be best?