I just got back from a family trip to Tahoe. We rented a lakeside house with a pier and buoy for 6 days. My dad towed his Nautique up from Lake Elsinore (SoCal) and we're so glad he did.
We had pretty awesome luck with the weather...it was upper 80s almost everyday (above average for late June). The water temp was low to mid 60s. The mornings were chilly and everyone wore wetsuits, but the afternoons were fine without suits for the adults. My kids (3/5/6) wore their wetsuits even in the afternoon when they were wakeboarding and tubing.
The entire lake was glassy from sunrise (about 5:30) until about 8:30 everyday. Still decent skiing and riding until about 10:00. After that it was tubing and surfing time until sundown, and a couple of the days it smoothed out in the evening.
We didn't see any crazy storms, it did get pretty windy one afternoon (35 mph or so out of the east/southeast). We moved the boat out to the buoy for that one, and kept it at the pier the rest of the time.
The highlights of the trip were the glassy bright blue water in the mornings and the cruise through emerald bay. We stayed in Carnelian Bay so it took us about 50 mins to get down to emerald bay. The low point of the trip was me tearing the meniscus in my right knee 10 days BEFORE the trip, so I became the default driver. I was able to surf but that was all.
If you're strapped on cash, maybe leave the boat at home. Gas is expensive up there, you'll have to get the mussel inspection ($100). The tow up through the mountains is a little steep too. My dad's 4.8L silverado did OK at best. But if you can afford it and you'll be there at least a few days I'd definitely bring it. You may have crappy weather, but you might just get the best session of your life.