Advice: 6 mths in Spain with young kids

My family is considering moving to Spain (likely Granada, but not absolutely set yet) for about 6 months. Another family will likely come with us. Between us, we'd have two preschool aged kids (4 and 3 years) and two babies. One parent in each family is fluent in Spanish, and a main goal of the trip is to expose the older two kids to as much Spanish as possible and help them progress their language skills in a fun and natural way. We're looking for advice from anyone else that may have done something similar, especially things to know in advance, logistical complications, recommendations. We're hoping to enroll the two older kids in a preschool there, if possible, and would love advice on short-ish term preschool enrollment or childcare in general. Our absolute ideal would be something like a forest preschool but we haven't found something like this in/near Granada yet. We're at the very earliest stages of dreaming this up, so open to any/all advice. Have you done something like this? We'd love to hear from you. Thanks.