This is a genuine question, not a quibble ...AFAI *Halloween* is derived from *All Hallows Even* so technically it should be *''Hallow''e'en*. That's a total of 5 ' s in place of: All, space, s, space & v.
As I recently wrote (and although I've very occasionally seen, maybe even used, it as a 'one-off' creation), I can't think of any commonly-used 'contracted word' that uses more than one apostrophe to represent 'missing letters', can you?
Looking at your 'example' above, I certainly don't think that there would ever be a need for two consecutive apostrophes, since we already accept that one apostrophe can represent two consecutive missing letters (as in " I'll " etc.), so I presume the same (just one apostrophe) could/would be used for more than two consecutive missing letters.
Indeed, there are (not all that common) situations in which, usually to considerably shorten a word (because of space of 'character count' limitations), one apostrophe represents many consecutive missing letters - such as " Int'l " for "International".
Kind Regards, John
