I just felt bad picturing 3 newborn chicks in a wire cage in the middle of a garage. Maybe if he posted a picture it wouldn't seem so cold. I'm in Wisconsin vs. Florida, so big difference there too!
Mine too. That's why we bought this one for $14 for the chicks.
https://www.amazon.com/gp/product/B07V1GZGR4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
That's what I would do. One of those heaters heating the area around the brooder should help that heat plate out.
If it still doesn't get them to 95F, do you have a heating pad that doesn't shut off? You could stick that in a pillow case (seal it in plastic first if it's not plastic...
Do you have an electric radiator-type room heater you could put in the general area of your brooder to help keep the temps up? You're right, that heat plate isn't going to cut it in those temps, but might do a better job with some help. Space heaters if that's what I'm thinking of scare me as...