Oh for size it might be 2ft by 3ft, he's napping now so I can't check it
We got rid of the sleep sack almost 2 months ago. I was worried too because she moves so much but she seems to move under the blanket or rolls back and forth with it. I still dress her in long sleeves and pants pjs and socks so she stays covered. The blanket is the size of those milestone picture blankets, not sure the actual size but pretty decently sized.
Mine still used a sleep sack with like 2-3 blankets and 2-3 stuffies 😂 I have a 18-24 sleep sack so it’s very long still and she loves sleeping with her blankets ever since she was 4 months old and more recently the stuffies
Around 13 months we just kinda gave him some pillows and a comforter in a big boy bed and watched the baby monitor very closely. He’s now 16 months and sleeps like a toddler, tucks himself him and just rests. We use a heavy sleep sack as well
We got rid of the sacks by 15 months because he'd play with the zipper, and I was afraid he'd faceplant into the rails in one. But I know ppl love them. He uses a crochet blanket. Sometimes he stays covered, others he doesn't. We did it during naps first to see how he did, then overnight