While programming is a process covering many stages, many of the tasks K-12 students meet at school are small with little need for, e.g., analysis or design. These earlier phases are, however, important to let children meet open-ended problems, brainstorm solutions and ideate their own creative designs. In this paper, we present a model for an online, scalable and scaffolded design workshop for covering such aspects at K-12 level. Through a case study with 1200 students and 60 teachers on IoT and smart things, we describe the workshop and the resulting designs. While the students managed to design their own artifacts, more time had been needed for covering ethical aspects related to technology design. The results suggest creating separate workshops for different grade levels, and also for design and ethical aspects respectively. Moreover, additional resources could support teachers in continuing the discussion with the students after the workshop.