I don't 'do' flowers but most of my 'laydees' do :(
I'd read/heard about the drastic hack-saw method with roses & suggested trying it as a last-ditch attempt to revive her roses, well-past their sell-by date, I'd reckoned, so did it late autumn 2 years ago.....nothing to lose cos these were going to be hoiked out in spring if it didn't work....
Complete success! They're still going strong and, indeed, now in their THIRD flush this crazy year 8)
Takes a leap of faith, tho, if it's something you really really want to keep?