Yeah you're probably good, that being said there are the containers in each campsite to keep your food. There are bears up in the Tahoe area but they are much less aggressive. Although I know near Lake Spaulding they use to relocate Yosemite bears up there. But at the camp that I worked at for the last 8 years, right next to Spaulding, we haven't had much in the way of bear problems for years.
Finding camping mid week shouldn't be an issue. There's plenty of free camping on nearby forest service land if for some reason you can't get camping when you arrive. Your food should be in the bear locker if it's in camp, but you'll have no problems whatsoever leaving food in your car.
I thought I read about some thefts this season of tents etc while climbers were up on the rock, so keep this in mind.