Every generation of CPU has high-power and low-power variants. The i9 is a high power variant that generates a lot of heat but what you want is the low power variant.

I recommend looking for a used laptop with a Core Ultra 7 165U (<$500) or a Core Ultra 7 268V (>$1000). Maybe an HP EliteBook. Either one would be faster than your old i9 and run much cooler.