He doesn't have covid. He's not dying.
I get that you're frightened, feeling out of control, your family is distressed and panicking, and that there is a lot of uncertainty, but you're massively catastrophising to be deciding you need to walk out of your job to go and say goodbye to a not-dying person.
(Also, he is a convict/inmate too - if he is following covid precautions why do you think none of his fellow convicts/inmates would? Prisoners are still as human as your dad.)
There are a lot of risks to an employer in agreeing for you to work remotely from another country because it means that they have to comply with the employment and tax laws in the other country - redundancy, health and safety, taxes, etc. It could also mean they end up being treated as trading in that country. I would be surprised if they agreed.
In your head he already has covid and is dying so you will only be gone for a matter of weeks.
In reality he does not have covid and is not dying. So how long would you stay there waiting for him to catch covid and die? Weeks? Months? Until the pandemic is "over"? Until he's released?
I'm sorry you're going through such a tough time. I really think you need to stop and take a breath before you do anything though. You're not being rational right now (understandably).