We're going in Nov and actually sat down a few weeks ago and went through our penny jar - we pulled out all the 1982 and before pennies - they were made differently and press better.
Funny thing is, I asked myself the same question a few weeks ago. I figured there might be 10 machines around WDW and we COULD get them all in one trip. - NOT!
I don't see getting, or even trying to get, all 494. But we have about 150 pennies we'll bring and we'll carry 10 or 20 each day and see what happens. If we get 10 or 20 for the whole trip, that'll be fine. DD5 loves 'em.
And no, I'm not carrying quarters. I'll ask for change at each location.
press on!