Kid friendly weekend getaway

My daughter will be 2 at the end of January and we were thinking of taking her a mini weekend vacation for her birthday since we've never been able to take her anywhere. We live south central Iowa (very far south) and are not wanting to drive more that 4-5 hours if possible. Since the weather is finally starting to get cold our options are limited. Does anyone have some idea's of a very kid friendly getaway where it would either be warmish in about a month or somewhere that offers a lot of indoor activities for a 2 year old.