There is discretion for the Home Office to overlook absences from the UK exceeding 450 days in the five years prior to applying for naturalisation, but there is no escaping the requirement that you must have been in the UK on a day precisely five years before the date of application. The Home Office simply have no power to waive this, however deserving the case...
So, March next year it is, then....
But I should say - and this is not the first time this question has arisen here - that you do not need to renew your present passport in order still to qualify for naturalisation. Clearly, you won't be able to travel if your passport isn't up to date - and that might or might not be a problem for you - but you will still be perfectly "legal" if you just let your present passport expire.
hth
paul