Play Room

We will have a bedroom available upstairs now that the oldest daughter is moving out (she's 20). My youngest son is 14 months and that will be his room. Should it solely be his bedroom or can it double as a play room? Should I still leave my front room as his play room as well? He's not allowed to climb up and down the stairs by himself so I'm afraid if I move all the toys upstairs, he will be bored down stairs. 
Any advice is welcome.