FYI I'd highly recommend North shore (Tahoe City/Kings Beach) over south shore. South is more commercial, strip malls, casinos, etc. North shore is generally quieter, and there are lots of trails accessible for hiking/biking.

It may be tough to find a VRBO that's available for a few months. Generally people have ski leases or summer leases set up in advance. You might also check local realtors.