On average I find there’s about a 3:1 ratio between overall weight and fillet weight on about any kind of fish, but specifically on channel cats. So an 8.8 lb channel cat should yield just under 3 lb of fillets.
So your question prompted me to go actually weight the fillets. Keep in mind they’ve been off the fish since yesterday AM, so they’ve lost some mass in terms of water, but the 2 biggest fillets were right around 1#6, so 2#12 together is just under 3#, as expected.
Now when I cook them up in the fryer, I cut off the skin side fat and cut out the lateral line, so figure just a bit more loss… probably about 2#8 altogether. Now consider that a double quarter pounder from McDonalds is 2 4-oz patties (pre-cooked) and you get an idea of how many people an 8# channel cat will feed.
I’m guessing it’d probably be a decent meal for 4 people if there were veggies and a salad?
That was probably more answer than you wanted, but since you asked and all, yanno?