They don't need all the money in one go for year one of college for the eldest.I am not so sure about this at all. Over ten years equities will probably outperform anything else. But if the OP is regularly saving the same amount every year for ten years for a big drawdown at the end then the average investment horizon is five years.
I agree. But many people misunderstand their needs and the risk involved in different investment options. Many think that deposit products, including State Savings, are somehow less risky than other options.It depends on OP's overall wealth, risk tolerance, future income, etc.
Equities is just one option. They're are others such as unit linked funds with a lower risk/reward profile. I really don't think that something like State Savings is a good option here.If I was on a fixed income with a big outgoing like kids' education coming up I'd probably just use state savings products due to mature around college time, certainly this approach by the kids are in late teens.
I don't understand that you mean here. Neither of the kids is 16.Continuing to put savings into an equity-type product to cover a a 17YO's college fees in a year's time seems pretty risky to me.
Anyway, as I said before, I also think that the original poster probably needs to do a Money Makeover post because it's not really possible to deal with this specific issue in isolation separate from an analysis of their overall financial situation.