I plan on staying in Reno in late March and driving to Squaw from Reno in a rental, do I need to consider the possibility of heavily snow covered roads, Do I need all wheel drive. I lived in Jersey and always had all wheel, so I have experience.

I would rent an all-wheel drive absolutely. we were there two weeks ago and there was a little bit of snow that ended on Sunday. Monday we went on route i-80 and got stopped in a chain control traffic jam because there was snow in the pass. They checked every single car for chains or all-wheel drive and if you didn't have all-wheel drive they made you get off. It was a pretty scary drive. Definitely rent all-wheel drive.

I'll be going up to squaw in late March, the snow is sooo much better than the East coast

In short yes, you are driving from high desert up even higher into the Sierras. And its always smart to be prepared. However if there are no storms, and no snow covered roads, then there is no requirement. It also depends on when you are coming out. I'd reserve a AWD vehicle if they'll let you. Otherwise get what you can get and just plan on staying in Reno if a snow storm arrives the same thing as you do.

There's been little snow this year and historically March is not a big snow month (if it snows at all). Come late March the roads will be clear and a two wheel drive car will be fine.