meads don't oxidise in the same way that "normal" wine does. So you should get a couple of days out of it, in the fridge!
It's just that a lot of people would drink it like a wine, but I'd suggest that historically, it's less likely to have been drunk in poncey little glasses and more like some sort of tankard type vessel - and logically, drunk more like beer!
Just my 2 pence worth.......
p.s. dunno whether the potential keeping properties has anything to do with the honey content....... archaeologists tasted some honey that had been in a tomb in Egypt for a couple of thousand years...... it was still edible......