Dad-son-grandson Patagonia trip in March

Me (47), my dad (78) and my son (20) are going on a 9 day trip to Argentina the first week of March - removing travel days we really only have a week - and we recognize this is a short period of time - but want to do BA + Patagonia. Our current plan involves arriving in BA on a Saturday with 2 nights in BA then fly to El Calafate on Monday and return to BA on Friday for one additional night before leaving on Saturday night back to the US. So 3 nights total in BA and 4 nights total in Patagonia. Any recommendations for how to best plan and what we must try to do in Patagonia are truly appreciated. My dad at 78 is in fairly good shape and is up for doing some moderate hikes. Looking for suggestions on tour operators, rental cars (yes or no) and hotels for the three of us to consider. TIA!