Hey potato, my boy is 5 months old too and has also been rolling for a while. He's also still wrapped. We wrap him with one arm out now, and put a mitten on the hand that is out and give him a muzzie to cuddle in that arm too, he puts it up by his face. This way eventually we can stop wrapping him and he'll still have the sleep cue of the muzzie.
Anyway with the rolling - you have a few options.... you could sleep him in a sleep wedge, which means he couldn't roll (but if he wriggles upwards it wouldn't be much help). Or you could try to wean him off the wrapping in the ezee rocker before putting him in the cot --- by first leaving one arm out for a few nights, and then the other one. (Though if your boy is anything like mine this wouldn't really work! Harry loves being wrapped). Or you could just leave him wrapped in the cot and watch him like a hawk for the first few daytime sleeps (trying to find somewhere where he can't see you). He may also like being wrapped with one arm out?
And just to put your mind at ease, my boy rolls if he's on the floor but not when he's wrapped and in bed