It is more accurate and sensible to consider the votes in pairwise groups, rather than simply tally their votes as a total of the 112 respondents. Because people voted for multiple options you have some votes that get double-counted if you don't filter out duplicate votes.
You're using the fact that 67 voted for a 66.7% threshold while 42 voted to keep it at 75% as a reason not to go all the way down to the lowest threshold despite the fact that 14 of those votes are by the same 7 people.
If you take the ratios as presented then lowering the threshold to 66.7% is 1.60x more popular than keeping it where it is (67/42)
However, If you eliminate the votes of users that voted for both options, and could be counted as abstaining, then lowering the threshold to 66.7% is 1.71x more popular than keeping it where it is (60/35)
If you consider lowering the threshold to 66.7 in isolation you have 60 yea, 35 nay, and 7 abstains for a total of 102 of your original 112 voters. 'Yea' won this pairwise poll by 63.1% of the vote, not 59.8%
This still does not meet your 2:1 threshold that you set, but it's a fair bit closer than you indicated.
This way of tallying votes gives too much power to people who voted for multiple options. 6 users voted for every option, meaning that he effectively abstained, but using this method they voted 4x more in favor of lowering the threshold than keeping it the same.