175kv heats up more for the same amps but also has more torque for the same amps
205kv heats less but has less torque
you can compensate for the lower torque with more amps if your esc can take it
If you are worried about power I’d go 205kv. If you don’t use the top speed you can gear down more maybe for even more torque, but if you keep the gearing it’s gonna be the same torque assuming you have the thermal headroom in the esc to up the amps so the motors heat up the same.
If your main worry is a very slight difference in range than probably 175kv is the better choice
size doesn’t matter for torque, only kv and amps
bigger sizes of the same quality and kv can take more amps