Its been a very long time since i skied in Lake Tahoe area, i live in Salt Lake City and we have many great ski areas, never need for snow chains.
Just got back from a trip to Southern Utah. Winter is sticking around this year and there is a lot of snow all around. On one excursion i drove Cathedral Valley loop when it started raining. Halfway into the 60 mile dirt road loop i had to drive down switchbacks covered by snow. But snow was relatively hard and porous spring snow, being careful and using 4wd i descended without a problem.
Snow can be very different with different temperatures. The "cold" snow is sticky and easy to drive on. The worst one is the Spring ice when snow melts during the day covering paved road with water then freezes overnight and creates thin layer of "black ice" which is extremely slippery and there is no grip even with 4wd. Finding the way aroung black ice is one way to continue.
There was only one time i put chains on my 2wd van on top of Kingsbury grade and 100 feet later removed them. Every time there is snow on the road it is an opportunity to parctice snow driving skills