Hank, I think you are in good shape if you have year one covered. You can do all the things suggested like tightening your belt, having your child take the $5500 loan (and stash it if you don’t need it), having child and spouse work and anything above the budget gets saved, etc. If you do all that, it is likely you’ll have enough money for year two. If the bonus comes in, that helps even more.
You’ve made a decision now make it work. Your original question was are there any loans out there with better terms than the PLUS loan. Not really. There may be a HELOC, there may be a credit union loan, but student loans like the PLUS loans have better protections and repayment terms than most private loans. You can check Sallie Mae and SoFi, but you’re going to ‘get’ something here and ‘give’ something there in terms or benefits.
You’ve got a handle on the numbers, now you need to do as suggested above and get a number for daughter to reach through her work this summer.
I also have a spendthrift kid and a saver kid. Both had the same budget for college and the spendthrift has more in loans. And a much lower paying job coming out of college. She’s going to have to work a couple of jobs to pay those student loans.