Sorry to stray before actually helping. My bad.

Bi-Wiring is generally defined as feeding a full range signal to an amp, going to the speaker with two pair of wires and discretely connecting the wires to distinct sections of the crossovers. This makes me laugh. Most of the theories around this one stem from folks envisioning the current surging down the wires. In fact at the frequencies and distances involved all points on any of the connected conductors see essentially the same voltage.

Bi-Amping (what you seem to want) generally refers to feeding a full range signal to a pair of amps and wiring each amp such that it drives a section of the crossover. This would isolate the two driver sections, but the amps are still driven full range. So although the current draw per amp would be reduced the onset of voltage clipping would be altered only a little in most cases. One advantage is that clipping in the bass amp would not blast harmonics into the tweeter.

The one that gives best results but is hardest to get right is Bi-Amping with active crossovers, where the amps are not driven full range. There can be benefits here, but the sonic characteristics of the speaker can also be easily compromised if done badly. This one works best inside powered speakers or if the manufacturer has specific provisions for it.

I'd just get a bigger amp.