Most banks you need to go a few days in advance and request your 12 month bank statement. You can only get the 6 month statement directly from your branch.
26 December when the visa expires immigration will be closed. So if you wait until they open you will be on overstay. Safest, do the border bounce, that cancels the visa and then return and you will then be stamped in on a 60 day tourist visa.
A few expats here use this company. Long term Insurance for retired people and they claim regular. Used the company for my mother when she visited for 3 months, did not have to claim.