The olives are local to the Girona region of Spain and ideally I'd like to at least get a couple of months of extra shelf life out of them. Is this possible?
Room temp while sealed in original package (per label recommendation or 2-3 years max).
Fridge in glass or plastic once opened, about 4-6 months.
Especially if it is heading into summer where you are you will want have them in a sealed container in the fridge. I find room temp is fine during the cooler months if I will eat then in about 2-3 months - if they are oil cured. I don't like cold olives so if serving them plain you can take what you want out of the jar to warm to room temp (it takes 30-45 min to come to room temp sitting in a bowl on the bench)