Probate confirms the will and formally names the executor with authority to act, and without it a buyer's lawyer will not release funds at possession. In Saskatchewan a straightforward application moves in a matter of weeks once the paperwork is complete, and takes considerably longer if the estate is contested or an asset is complicated to value.
You do not have to wait idle. Listing the Adelaide/Churchill house, marketing it and even accepting an offer can happen while the grant is still moving through the court, provided the purchase agreement carries a condition tied to receiving probate before the sale can close. Budget for your own lawyer's fee of roughly $800 to $1,500 on the transfer itself, separate from the estate's legal costs.
The Canada Revenue Agency treats the date of death as a deemed disposition at fair market value, so a valuation dated close to that day matters for the estate's tax return as well as for setting the eventual list price. Get your hand-reviewed valuation from Joel Dyck.