you´re not going off the fence if you initiate actions right at V1. An enormous set of unfortunate things should take place for that to happen.
1) improperly executed maneuvers
2) figures not correct (last minute wt adjustments or excess baggage not declared)
3) unconsidered wind changes
4) a performance deterioration factor not kept in mind
5) excessively worn out brakes
etc.......
Besides keep in mind that for a certain weight, flap, temperature, and wind, V1 is the same in a 6000 ft rwy as in a 12000 ft rwy (except improved climb) so you´re in one scenario you´re not going to go off the fence, no matter what..and the other one you might if things (or you) don´t perform as expected. V1 is generally unrelated to rwy length.....generally.