Funds remain in the deceased's account until probate is granted. Cannot be accessed before then. Usually, unless there are complications, once probate is granted the funds can be distributed relatively quickly. The solicitor must take guidance from the executor on what to do with the funds if distribution cannot take place immediately.
Some solicitors offices would charge an administration cost to set up a high interest deposit account and depending on the time involved one cost might cancel out the other. Furthermore under solicitors regulations solicitors are obliged to account to their clients for any interest over one hundred euro.