Do your parents or in-laws provide childcare? Tell me what you'd do in this situation...?

You will need "care" of one kind or another for at least 8 to 12 years depending on the child and your circumstances - you are asking your in-laws for a lot. Its a committment they may at a later time be unable to do... I think you should look for a nanny or in home care provider instead and let the grandparents take the kids when they want to and when it convenient for them.