For our project, we decided to do something risky but creative to tackle the issue of crossing the gap. Considering the 45 minute time constraint, we still were able to cross the EV3  a maximum of 13 inches across.  We achieved this by basically mounting an EV3 and a motor with a tire on top of an 18 inch beam structure that was controlled by two motors. The robot was placed near the edge and then the beam would be swung down taking the brick and motor to the other side. Then the motor near the brick would start and drag the remaining robot to the other side.

The program is not complicated. It just brings the beams down and then moves it across.

Unfortunately, our robot fell off the table and completely broke apart while trying out 15 inches gap so we do not have a lot more photos or an explanation video but there is a video of it (barely) crossing the brick 13 inches below.