Nobody can predict how much time Donald Trump would spend in prison if found guilty. However, the Espionage Act carries a maximum sentence of ten years. The tampering and concealment charge carries a maximum sentence of 20 years. The Scheme to Conceal and False Statements carries a maximum sentence of five years. These are all guidelines and there are other factors to consider in sentencing, like being a first-time offender, remorse or lack of it, his goading others to commit crimes, and biased Trumper judge, etc, etc.
But the case in Miami isn’t the only one Trump is facing that can give him prison time. He’s still facing potential charges in Georgia over election tampering and for his actions in the January 6 insurrection attempt. Trump is going to be charged in those cases and will face different juries and judges.
I’m cynical and won’t believe Trump is going to prison until I see it, but I know that Donald Trump deserves to have the rest of his birthdays in federal prison.