:indulge in the noble art of faking, a skill well known to 2 row diatonic (melodeon) players. eg you could
as you say go up an octave which with practice might not brake up the flow if done smoothly
substitiute a singe bass note for the missing low treble note,
play the note before the one you hav.t got twice,
leave a gap ( fine if playing with other instruments that have the required low note(s)
cause a diversion on the bass by going a wee bit heavy to distract attention from the missing note
come up with a slightly different 'arrangement'' i.e change the note you havn't got for one you have got.
etc etc etc
When 'faking' you will to begin with be acutely aware that you are not playing a tune ''correctly'' particularly if you are a reader. However it is unlikely that the average punter will even notice the slight change of 'arrangement' provided it is done with aplomb and without apologies
george (a good faker!)
