If you are in danger of paying your mortgage late, send your payment via overnight mail. The cost of doing so is probably much less than your late payment. For example, a 5% late penalty on a $1,000 payment is $50. Sending the payment via Federal Express will cost you less than $15.
Look for dirty spots in your insulation, which often indicate holes where air leaks into and out of your house. You can seal the holes by stapling sheets of plastic over the holes and caulking the edges of the plastic.