if you want to minimize your risks of refusal, then get a loan or use your credit card, pay off your over draft
and have a few £,000s in the bank until dec. then once you've applied for your visa, pay the CC off.
well maybe you could live partly off your credit card for the next few months, and leave as much of your wages in the bank as possible, so over next couple of months your bank statements will look a lot healthier,
and hopefully show a couple of £,000s in savings , then again once you've applied, pay the CC off.and mention in your letter of support why your earlier statements showed an overdraft, eg trips to see your g/f, hols or what ever