Thats all. I'm not expecting to make a visa app with our finances the way they are atm.
But if you did the budget for 6 months and not for a year, then you meet the requirements for the finances, so why not just adjust your budget and apply now?
For example:
Income£2300/6 months = £383.33
Lodger = £350
Total = £733.33
OutgoingsMortgage and Council Tax = £228.83
Amount needed for visa = £424
Total left after mortgage and council tax = £505
Other outgoings (taking out £100 for entertainment as WebyJ suggested) = £450
Money leftover = + £55