Thanks for the replies & links. Looks like I need to book the 6:30AM flt. and then I'll be OK.
Now, if I oversleep & arrive at the airport before 8:30AM I should be able to pay $25 & get a SDC seat on the 11:30AM flt., assuming there are seats available. Right? Or, get up at 6:00-6:30AM and do it online?
Then my luggage will arrive in BOI w/o me and I can pick it up when I arrive later in the day. Right?