You need the right amount of snow. A moderate amount makes the PAXes want someone else to do the driving and more ants want to stay home, but too much makes it take twice as long to get where you are going and therefore fewer rides taken - negates the surge.
Still had my all seasons on so didn't risk it. Once the winters are on next week I'll be good to go in all conditions. In the next 6 weeks I'm going to try going max effort to see how much value I can extract from my car.
One thing I found driving last year I would max out the long pickup fee when conditions were super shit and I was going half the speed limit to the pickup.