If a property is unsold, it's a bit previous to speak in terms of the estate being wound up. But that is only a quibble on terminology.
Some executors (and, it seems to me, particularly solicitors acting as or for executors) like everything to be sorted before making any disbursement. My opinion is that a partial disbursement is fine provided that the executor is not left short of funds to deal with outstanding matters. Bear in mind that it might take some time to sell a property, and there cane be ongoing costs such as insurance, LPT, possibly some repairs, and so on.