The only sensible strategy is to pay as go. No reason at all why you can't pay a £1,000 a day by instant debit card if need be. Then your exposure is minimal. If they offer an upfront payment discount tell them you want the discount but without the upfront requirement or your business goes to a competitor. Turning away turn over is something none of the FTO's are in a position to do right now.
Bloody good advice. Flight training is a buyers market right now, make the most of it.