How viable would it be use CCA drones to intercept and sacrifice themselves to incoming missiles?
Assuming the "incoming missiles" you mentioned are referring to air-to-air missiles (A2A):
Doing so is exceptionally wasteful, especially considering that all the (currently known) CCA-type UCAVs that the PLAAF and PLANAF are expected to operate are of the medium and high-tiers, meeaning that they're going to be more sophisticated and (understandably) more expensive.
In fact, each AAM would cost less than individual CCA-type UCAV.
In other words - This will only ever be considered as a defense mechanism of last-resort, i.e. self-sacrifice in order to protect allied manned command platforms (fighters, bombers, special mission aircrafts etc) from incoming enemy missiles.
How about a drone carrier that deploys smaller drones that fly towards the missiles, and explode with a cone of a million pellets/mini bombs or intercept them directly?
It's exceptionally difficult to intercept smaller objects flying at Mach 4-5 (let alone highly maneuverable ones) than larger objects flying at Mach 1-2 at most.
(For the former: The PL-15, PL-16, PL-17, PL-XX etc says "Hehe")
That's why while there certainly are efforts by countries to develop such hard-kill measures, none have been successfully developed/fielded so far.
The most promising/prospective hard-kill measure envisioned so far would be the aircraft-mounted anti-air laser systems, but due to its immense power requirement, it remains to be seen whether they can be fitted on fighters instead of just larger aircrafts (i.e. bombers, transporters, tankers and special mission aircrafts).