...Interesting though, the winter of 2011, the road to Horseshoe Meadows didn't open until, I believe mid-June.
That's possible. From my logs I did Whitney on May 7, 2011, but getting to Horseshoe Meadows is a few thousand feet higher than the Portal, and the exposure is different.
I read Saltydog's suggested workarounds for alternative routes, and frankly am a bit dubious. I lived in Inyokern for several years, and made dozens of trips to Horseshoe Meadows, so am somewhat familiar with the area. I've hiked to Owens Point a couple of times - it's on the ridge over looking the drainages above the De La Cour Ranch - and listened to the stories of cattle being driven over the edge (it's about 11K') and the dubious survival rate. It's damn steep. I can't imagine trying to hike up it. And have hiked (and done trail maintenance) in the Cottonwood canyon area he mentioned. Years ago there was a sluice from about Cottonwood Meadows down to the valley floor, and pinyon pines are cut and sent down the sluice. The old sawmill is downhill, just east of the existing road. Once in the valley the logs were converted to charcoal, and this was transported across Owens Lake (yup, it really did have water at one time) to the silver smelter at the Cerro Gordo mine located in the Inyo Mountains on the other side of the Owens Valley. Little remains of the sluice (rot and avalanches) but as you work your way up the canyon you can sometimes see remains. You can drive up the road as LADPW maintains it to a certain point, and then begin the hike. But - about all I've wanted to do in a day is about 3.5 miles in before heading out. The canyon is beautiful, with an elevation gain of about 1K'/mile. 3.5 miles in would still leave about 2 miles of hiking and 2K' of gain to reach the road. So, if you had 2 vehicles, a great day hike would be to spot one car up on the road, and then drive around and start the hike at the end of the pavement near the LADPW building.
In any case - if it were me, and I really wanted to get to CM before the road was repaired, I'd drive as far as I could on the highway, and hoof it up the road. Any other approach would be its own adventure.