Originally Posted by say chi sin lo
I'm going to assume you also have a manual gearbox? When you can engine brake on the demand, you have more control.
Why do you say that? When you lose control on ice/snow, it happens because of insufficient friction between your tires and the road. No matter how you slow the rotation of your wheels (through brake pads, engine braking, or baseball cards in the spoke), your control is determined by (a) your tires and (b) how abruptly you stop the wheel rotation.
Sure, it is easy to slow the wheels too quickly by slamming on the brake. But it's also easy to slow the wheels too quickly by downshifting too aggressively. Both brakes and engine braking allow a whole range of braking force. Neither is better or worse for control, though most people probably have a preference based on what they use most.
Re: snow tires vs all seasons. Sure, you usually can get away with all seasons and AWD. But is "good enough" really what you want on an icy mountain road? A FWD economy car with chains on is better in snow and ice than an AWD with crappy all seasons. Some all seasons are better on snow than others, and with a rental you probably have no control over which one you get. You could also try renting a car IN the Tahoe area, there you would probably be more likely to get adequate tires on the vehicle.