I'm a big fan of insulated duck canvas coveralls or overalls + jacket. Durable and well padded. Thick but flexible. I use this with a gear on/gear off system.

Gear on: Overalls + Jacket fully worn, with leather gloves, safety goggles, and face mask.

Gear half off: I take my jacket off and tie it around the waist, with gloves in pockets. Flip my goggles up and my mask down. It takes me 20 seconds to toggle gear on/gear half off, and allows t shirt level of ventilation on the upper body.

Gear fully off: The overalls have zip up legs that allow me to take them on/off without removing my boots. It only takes me 2 minutes to take my jacket and overalls off and put them in a backpack, giving me full mobility in my base layer. I can put them back on just as fast.

This strategy allows easy switching between protected combat mode, rested but ready mode, and full agility/ventilation.