Some insurance carriers require that the car reside or be garaged in the state in which it is being insured for a certain portion of the year. It would appear that your insurance companies is one such provider and that their guidelines do not allow them to continue the current insurance policy and coverage on your cars since you and your vehicles are residing out of state for an extended period of time.

If you really want to keep Illinois insurance on your vehicle, check with the IL Department of Insurance to see if this is allowable according to state laws or if you will need to get Iowa car insurance since you are going to be living and driving your vehicles out of state for a full year.

If find from the IL DOI that you can keep in Illinois auto insurance, see if there is a different Illinois insurance company that will provide you the coverage you need. Or instead you might decide to get car insurance in Iowa for the year that you will be living there and then switch back to IL auto insurance once you return back to your home state. 

For affordable auto insurance quotes for either Illinois or Iowa, chick here.