but how long they'll last depends very much on how long the cold weather lasts.
We're currently importing a lot of grit from Egypt.
Outside my wife's clinic there's one of those roadside salt bins for the use of local residents. Yesterday morning it was filled up by the council.
Yesterday afternoon a large white van pulled up, and three men jumped out, shovelled the entire bin-full of road salt into the back, and drove off. One of the patients said these people are touring the suburban streets selling people bags of salt - the same salt they've already paid for via their council tax.
When I lived in Forest Hill/Lewisham we had a salt bin at the top of the very steep hill where we lived . The council removed it and when we queried why we were told that it was because of vandalism and theft! Presumably a similar situation to what you describe. The local Vicar at the time took to walking to the local council salt dump with a wheelbarrow. The road was a dead end so was not on the council gritting priority list despite there being over 200 households isolated at the top of the very steep hill.