My 1yo hates Grobags. He is a wriggler and I think it restricts his movement hence why he wont sleep in them. I have got him the 2.5 tog sleepsuits from Mothercare which are working fine but I am worried about when it is really cold or in the day when he is going down for his nap. I cant really put those suits over his clothes. Can I use a light duvet/blanket for him? Worried he will get tangled...