Would the earthworks m23 work with this setup?
I see no reason why the Earthworks m23 wouldn't work with this setup. Use a battery power phantom power adapter such as the Countryman Battery Power Module AXBPM, which provides 18V phantom power, which is sufficient for the M23. On my Lectrosonics HM transmitter, I have mine set to 15 volts mic power, and my M23 works fine with that voltage. Considering that the Line 6 XD-V70L systems are discontinued and dealers are selling off old stock, you might be able find a good deal on one. Hmm, this is very tempting!
The only caveat in using phantom power supplies with less voltage output is that the microphone loses a few dB of headroom, but considering the Max Acoustic input of the M23 is 142 dB SPL with 48 volt phantom power, I don't think you'd be measuring at that high a level anyway, or even a couple dB less! I certainly wouldn't want to be in such conditions!