I was using a prediction, 1:10, standard for 1-week jams like this. Problem is I didn't account properly for audience, since a jam with a pre-existing audience of this size is (obviously now, but I guess hindsight is 20/20) going to have a higher submission rate, which it did, and that's my bad.
To be honest, the voting period was going to be this long either way. We have 10 judges and 129 entries, and finding new judges that are trustworthy enough in this case is extremely difficult. Only real effect of not quite being ready for the amount of entries is that I keep having to push the end date back to adjust for it. This should be the final delay as some of the judges are starting to make extremely quick progress.