i worked out a similar question/answer scenario years ago, when i toured full time.
i ended up with (2) 1x12's (i now have 3 1x12's, more on that shortly)
with a pair of 1x12's, you'll not get the oomph and bottom you CAN get out of a 2x12, but honestly, the mic, on a live stage, hardly hears the difference.
it hears the close proximity of a single 12" speaker.
(RECORDING, IS A COMPLETELY DIFFERENT TOPIC)
anyways.....
i had the option of being able to rotate the cabinets in a multitude of arrangments...
- *both on the floor, facing outward, at max volume;
*both stacked, facing outward, for having stage volume, and also being able to monitor myself better;
one forward, and one backward, with a mic on it, for a somewhat controlled micing situation that mitigated some stage volume;
*one backwards, with a mic on it, and the other cross-stage, for the fellow musicians to hear me better;
*both backwards, in shallow stages, where i can monitor myself off the wall behind me, and play loud as *****, without it killing people at the edge of the stage;
*one backwards, with a mic on it, and the other in front of me, angled up, like a monitor, for very low-volume playing (this worked like a charm, the rest of the band could hear me, the soundman had complete control of my mix FOH).
now with (3) 1x12's, i have a live rig, that allows me to do a dry/wet setup.
the center cab, comes straight off the boogie, dry, and unaffected.
the fx loop out, goes to a secondary stereo amp (set up for clean) and the preamp and effects sound of the boogie, goes out left and right to the two other 1x12's, for a pure stereo fx setup. i can run the FX full time/all time, or i can run the send from the fx loop thru a volume pedal, and blend the fx sounds in and out at will, in stereo, tho this is a bit trickier without a mixer in the line to blend the amount of fx, it still works really well, if the fx are not to 'wet'.