Absolutely fix-able. Glad y’all mentioned that, the temperature thing, oddly, hadn’t even occurred to me. Or, to whatever extent it did, I thought a few hours in the fridge would have reversed its effects.
FWIW, when I make egg salad, I mix the solid ingredients first, then add enough mayonnaise to get it to the desired consistency. I don’t measure, but it doesn’t take much mayo.
Mayo is the only liquid ingredient in my salad, though. Otherwise it’s egg, celery, onion (not dried, though - fresh), salt, pepper. Sometimes I add curry powder.
That’s a nice-sounding recipe, Manduck. Thanks!
No mayo is an emulsion. One it destabilizes due to either high temps or chemical interaction it’s not going to “re-set” in a cool environment.
Don’t tell Alton I forgot, m’kay?
I’ve never made more egg salad than I planned on eating immediately. Also, while I might sometimes feel the need for pickles, I’d rather just chop up a pickle instead of using relish. Relish is generally too sweet and watery for egg salad if you ask me. I don’t measure anything either; I just add a glob of mayo, a squirt of brown mustard, a chopped pickle if I feel like it, and a couple shakes of pepper. There should be just enough mayo to moisten the eggs and bind them together, but no more (likewise with tuna or chicken salad). Too much mayo and I might as well just eat it straight out of the jar.
If you want perfect boiled eggs, get one of these. It’s scientific!
Thank for the timer recommendation, sturmhauke, but in true Alton-disciple fashion, I’m trying hard to keep unitaskers out of my kitchen. Except that one under the sink, of course. 
I can fix this one!
I cut my eggs in half and pop out the yolk. I mash the yolk up with the other ingredients, and then add the diced whites. I use an egg slicer on the whites.
I agree in principle with keeping gadgets to a minimum, but I think Alton can be overzealous on that. Some of his workarounds seem like more trouble than they’re worth.
Hey, a timer can be useful for timing other things too. 
You don’t have to get an egg timer, but some kind of digital, programmable timer with alarm can be quite a handy thing.
No question about it, and I have one on my microwave. Until I get to the point that I’m timing more than one thing at a time, that works fine for me.
Thanks to everyone for the suggestions. I made up a batch at dinner and it’s consistency is much closer to what I think of when I think of egg salad. I only used 3 eggs (I had a nom attack), but they were well-cooled, and I put in about 2 tbsp. of mayo (1 didn’t seem nearly enough as I was mixing), about 1 tsp. mustard, and then just some pepper and onion salt, since that was what I pulled down out of the cabinet when I reached for minced onion.
At this point, I’m thinking the problem was a combination of too much wet team, including the specific over-wetness of the relish, and warm eggs.
I haven’t tried my new recipe yet (except for cleaning the fork I used to mix it up), so I don’t yet know if I will really miss the relish. To tell the truth, the only reason I used the relish to begin with is because I put it in tuna salad, and thought it would taste good with the eggs, too.