I've done that kind of gig before, with my guitar and vocal coming out of a wedge in front of me. For that idea to be painless, you would want to know at least a couple of things before you get to the venue.
Are the house monitors any good?
How many monitor mixes are available? You would need your own separate mix to be able to hear yourself well enough, without being too loud for other people.
I use only IEM and no floor wedges or stage volume and love it--so does my hearing. 
J
For me this gigs with local monitor cabs are still a HORROR! I guess I will also try in ear monitoring some day soon although they have one critical downside on smaller and medium sized gigs where we have very often not all the instruments in the PA. I would need to set up my own mics and bring a small mixer for this purpose - which in a way spoils the idea of bringing the Kemper and only the Kemper.
I had several gigs where I brought an AER compact 60. It adds only 6 Kg to the weight of my luggage and works quite ok as a monitor pointing back towards me. But it is as big and as heavy as the Kemper.
But remember this: if you send two signals to the mixer, one from the Main Out (for FOH) and one from the Monitor Out (for return to your monitor wedge) you can at least have a bit more control over your monitor sound. This helps a bit.
If the EQ in the Monitor Out section is not enough you can also set up a studio EQ in the Mod Slot and set the Main Out to "stack out". But this means you loose all the possibilities of the effect section for the FOH but you gain more options to eq the Monitor Out to crappy PA. It is a pity that the Kemper team does not consider to give the Monitor Out EQ at least one more fully parametric band for this purpose. Read here and here.
