How long can a Resistance Heating wire last until it cannot be used anymore?
That's about 980-1093 °C, which is well beyond cherry red.

Things like hair dryers operate their elements around cherry red and electric bar heaters are about 900 °C, so you are going a bit beyond what is normally used for Nichrome. The hair dryers I've seen the insides of have the element supported on mica; electric bar heaters have the wire mounted on a refractory ceramic support, so you might need to do the same to avoid the wire drooping.

Looking around a bit, I found something about the cones used to measure temperature in clay-firing kilns which suggests to me that you would need an earthenware or porcelain support to avoid the actual support melting. I suspect, and you should confirm, that red clay is what household bricks are made of and that would not be sufficiently heat-resistant with a safety margin in mind.

I suggest that the answer is to do an experiment yourself - and make sure that nothing can catch fire around the experiment that you can't put out with the fire extinguisher that you have to hand.