How long it will last, who knows, sooner or later cross border sales of tobacco will be banned, but for the time being those who can are stocking up while they can. Cigars last for decades and peak in the 5-25 year range depending on the cigar so right now there's no downside to buying as many as you can, even the none special editions (cuban) are probably good for about 10% a year in appreciation.
Personally I'm buying a box a month.