I believe that contracts in foreign currency are legally binding in Argentina, and even bank mortgages denominated in Dollars, requiring repayment in Dollars, have been upheld by the local courts.
For many expats, an optimal scenario involves a rental agreement in Dollars with payments made from offshore accounts. Otherwise, there might be the necessity to physically bring in the cash and, in the rare instance that peso payment is favored, convert it to Pesos. Regardless, the contract itself would remain legally valid; however, how the property owner handles the rental payments becomes a separate matter.
However, it's worth noting that paying utility bills in Dollars is not possible. Only In pesos.
Based on my experience the past few weeks the owners do not want bank transfers to an overseas account. They want the actual cash in hand.