Look at the stamp date on yiur Pass Port ....it shoukd have a late Decenber date that you can extend fir 30 days so late January spend a few days in Cambodia and fly back and start again.
I lived in the same condo 10 months a year....paid 12 months rental as it was cheaper than paying twelve months. Apart from a letter from manager when I applied for my "retirement visa" and renewals I never did any other paperwork. Only did 2 90day reports in 7 years.
That was Chiang Mai.
I traveled out of Thailand at least three times a year.
Suggest you try Pacific Prime....they are Health Insurance Broker...give the. Your country eg Thailand and requirements and they will give yiu options that might suit your budget.