$1,500 – from state of Idaho. This is a one-time windfall.
$700 – from your employer. Is this every year? Or just a one-time payment?
$5,685 – Pell grant (this is approximate; you don’t know exactly what you’ll get). We’ll assume this is every year.
TOTAL is $7,885 – not “approximately $9,000”.
The cost of attendance for THIS year (2016-2017) is $19,210. It will be more next year, 2017-2018.
You have a shortfall of at least $11,325. Let’s say $12,000 for a round number.
You will probably be offered work-study. You’d have to get a work-study job on campus. That will probably be about $3,000, which you get as you work, not up front.
You might be eligible for SEOG and some of the other need-based grants that are listed on the website:
http://www.collegedata.com/cs/data/college/college_pg03_tmpl.jhtml?schoolId=1082
But you won’t know until you get your award notification.
And all the above is just for your first year. You won’t get the $1,500 from the state, and I’m not sure the $700 from your employer will be there your sophomore, junior, and senior years. Assuming your family’s financial situation remains the same, the only money you can count on is the $5700(approx) Pell grant and $3,000 in work-study. OF course, you can take out the subsidized loan for $5,500, but you said you don’t want to.
You say that you were taught to always plan ahead. It is much more important for you to plan ahead for how you will pay than for whether you should request a double or a single.