MerylStreep
Buy a small handheld. Not Dyson. IMPO.
I do find my old handheld Dyson vacuum cleaner good although the newer animal full-size rechargeable isn't.
The handheld one has an attachment which is good for doing stairs.
Presumably your large Miele has an extendable hose which would reach at least halfway up?
However, if you find it difficult to carry a vacuum cleaner up and downstairs it might be better to invest in a lightweight, full size rechargeable for upstairs.
Better than having an accident.