Re: Some serious questions about thyroid problems...
Its nearly impossible these days to not be close to a pharmacy. This topic has come up here in the past. First, if you had not had your thyroid removed from surgery, whatever is left would probably swell up in an effort to pump out more hormone, keeping you alive for several days. Next, even without a thyroid, death is not spur of the moment. The residual thyroid in your system should keep you alive and fairly functional for a few days at least. As the thyroid levels in your system falls, you would obviously become worse and worse off, turning really hypo.
If you were stranded on a deserted island you would shoot or trap some wild pigs (preferably) or other wild animals and with surgical precision remove and cook up the thyroid gland and eat it. This would give you the hormone you need too but it would be extremely difficult to regulate obviously.
If you were stuck somewhere with limited meds, you would probably opt to turn yourself a little hypo by rationing your dose, splitting each pill you have left into quarters or eighths so you can get at least some hormone for a prolonged period of time. A little hypo is better than dead.
Other than that, you would pretty much be up a creek eventually.