FWIW (do take into consideration my thin-blooded Floridian-ness

), I'm approaching the race outfit as I would a park day: layers, layers, layers.
I'm doing a Snow White-inspired outfit: short sleeve blue tech tee; I'll wear a long-sleeve compression tee under it and if we get some freak heat wave, I'm adept at removing that long sleeve tee with the short sleeve one still on. I'll wear a blue fleece I bought on sale for $9 over all for however long I need to stay warm in the corral/get warmed up in the race, then toss it.
On the bottom: tights under a yellow sparkly skirt. I have full-length leg warmers to wear over the tights and can toss them easily when ready. I also have an old pair of baggy blue sweats I can wear on top if needed in the corral.
Accessories: hat, ear warmer, knit gloves.
Early morning in late Feb., I KNOW I won't be hot; I'd rather err on the side of too many layers and tossing some than being too cold to move. But again - I'm Floridian and just ran comfortably in 2 layers in 55 degrees. YMMV.
Are you strictly walking or doing some run intervals? My walking pace is around 15:30, but just throwing in a 30-sec run every few mins reduces that quickly. As for knee pain, I never feel ITBS pain when walking, but it's worth checking into. I'd also make sure you're in the right shoes for your walking gait; I've found I need much more support for walking than I do running.
I'm a frequent CSR guest...
I like all sections, but if you want to be close to food and the expo, I'd request Casitas.
Bus stops are all pretty convenient to rooms.
It's a HIKE from the Ranchos section to the main building - if you want to be closer, request Casitas or Cabanas.
Don't know about race buses.
The main Dig Site pool is pretty cool.
I'm not a fan of any CSR restaurants... but the gelato sold in the QS place is fantastic!