1) Youtube the spectator spots to see which ones look most appealing to you. It's always a blast no matter what, between the people, cars, and shenanigans. It pays to get to the stages an hour before first car out if you are picky about the view. Plus, it gives you more time to meet people.
2) The roads are usually plowed, with compacted snow/ice on the roads leading to the stages. People do get around on all-seasons, though most have snows.
3) At this point, stay where ever you can find. As has been said, most places are booked by now.
Bring a backpack/satchel/man purse with food and water, and extra layers. You will be out in the cold for awhile, and the temps can drop to single digits very quickly. Hop on Amazon, and buy a big box of hand warmers.
There are a few groups from the Indy area, Gonq area, and other regions that always head up. If you happen to run into one of those groups, you'll more than likely be allowed to caravan with them to and around the stages, provided you know the secret handshake.
And be sure to look out for #267 in Open Light!