I'm pretty sure it's exactly the same size as a Starcaster. Warmoth is licensed to manufacture Fender parts, so they have no reason to fudge specs to avoid lawsuits.
But, so you know...
upper bout width = 10 3/4"
waist width = 9"
lower bout width = 14"
body length = 18"
thickest point including TOM bridge ~3"
overall length w/ Strat neck = 38 1/2"
It's sort of an offset design so it's difficult to measure exactly, but those numbers should be good within 1/4".
Good luck finding a case. Close as I can tell, you can't get there from here, and I've looked extensively. You're probably going to end up with an oversized case that you'll have to stuff with pillows or something.