How long is a piece of red tape? How long it takes to get probate depends on a number of things: how much and what kinds of property, the deceased had (mostly delay through agreeing valuations and reliefs), how complicated the estate is (trusts involved etc) and, above all , the snail's pace at which the Office operates. You can generally agree a working liability and then pay that and leave the arguments about what else is or isn't payable to later; gifts in lifetime can involve a lot of discussion, as can strange things like whether a house is eligible for relief as the home of a deceased working farmer, but all for later.
I'd say it's 3 to 4 months in a fairly straightforward case, allowing for the snail. Of course, that may not be everything, but it gets probate. After that , to wind up the estate fully may take a month, or, in in the estate of my late mother (not that unusual, but full of tax arguments), 4 years !