Depends how soon you will need the cot for next bub!
Also, I haven't moved DD (2yrs) because I know she would be out of bed in a flash at nap times and bed times and anytime she feels like it and I would be the one getting her back in all the time so she stays in the cot! Chn this age don't understand discipline so what would you do if he continually got out of bed at night? Would it be you or your husband getting him to settle in it day and night?
If the mattress to floor distance is small I wouldn't worry about him rolling out!
It will be the first of many issues you will have to compromise on. I think the adult who has to deal with the consequences of decisions get to make them!