Just ordered my tyvek paint suits for the corral and packing so many throw away clothes. So, my only worry now is if I slow down during the marathon and getting cold then. . . Go Dopey!
I bought Tyvek jackets on
Amazon for corral use. For last year’s half, it was warm enough I wound up checking the jacket,,, and wound up wearing it later as a rain jacket when the downpour hit. Highly recommended.
FWIW, I’ll wear tights as part of costuming, but otherwise don’t feel the cold on my legs enough to wear more than shorts, at least in my typical race temps (down to the low 40s), so just the jacket.
One of my first MW races had a rather chilly start temp, like low 40’s, so I kept the sweatshirt on until just outside the MK, then tossed it aside (photos > warmth), but was warm enough from then on with the sun coming up.
If I think it’ll be cold enough the whole race, just wear another layer under my costume.
Gloves: last year I started to notice how my hands were cold even if the rest of me wasn’t, so if I was about to be heading down there, I’d be acquiring some cheap gloves to toss or thin ones I can tuck in my pocket. For training runs, I like my thin motorcycle under-gloves meant to be worn under the larger main gloves. The under gloves are wind proof and do the job, but very compact in a pocket.
YMMV
Good luck on the Dopey!