Yeah, it is supposed to work in other bases.

However your math is a bit misleading, just because you convert the digits to base-5 you would still have the same number of votes, since each digit representation still only counts as 1 vote and we express numbers for statistical validity in base 10.

Of course you could convert EVERYTHING to base-5 including the statistical validity, but that is unnecessary. Just convert the digits to base-5, but you still have the same votes. Regardless, 15000 votes do not necessarily span many orders of magnitude, since ever precinct could have the same number of votes, say 1000 for example. But its possible that each precinct saw very different numbers of votes, in which case you would observe 10 in one, and maybe 1000 in another and maybe 5000 in another.