I am aware that the choice of Frogmore Cottage has surprised many who thought they had it all sorted but nowhere in all that debating was Frogmore Cottage raised. At some stage it had been turned into 5 flats by only 2 were occupied as it was too far from everything to entice even most staff.
HM has always maintained Frogmore was the family's special place and since the Castle and grounds are open to the public for large amounts of time Frogmore, that Estate within Windsor, was not open to the public except for garden enthusiasts three days a year. All tours are guided and nobody can just wander off.
So, the internal road by the Cottage is a private road used by gardeners, etc. and I am sure that with things being the way they are, another layer of security will be in place when the Sussexes move in.
I love old houses and this one is a beauty. From a home for a lesser royal to a sixteen bedroom bachelor annex for hunting season and then, after WWII, divided into flats and now it is returning to its original purpose.
I think HM was reluctant to have anyone other than staff there because it is within that wonderful Frogmore park where they would all picnic and play and relax in privacy when the children were young.