Continuing the Online Activities Within or Without the Classroom

From my teaching experiences, I usually had difficulty planning the time frame for the online activities--more specifically, writing--because the activities usually take a lot of time. Lessons usually are taught for about 10-15 minutes, followed by a writing activity for the remaining 30-35 minutes. More often than not, with the given amount of time, they do not finish their tasks.

The reason why this is important for me is that a lot of the time spent in our class is spent on writing inside the classroom, and this limitation usually makes the lessons slow and dragging, especially if there are more topics to be covered. 

Should I take advantage of the availability of this learning space outside the classroom, beyond class hours? Or should I make them use the class hours more for these types of online activities?

Which of these options do you prefer?