If you had to get stuck with either one
Too big, not that such a thing exists.
Blanket too big? Does not compute. Blanket too small? Something is gonna be cold. No thanks.
Seriously, how is a blanket too big? It can always be folded or only partially used. Too small, that’s definitely a problem and do not want.
I’m with you guys. Too big a blanket is like too many pillows, it just doesn’t exist in my world.
This. A blanket bigger than the bed can be worked around, but you can’t stretch a too-small blanket bigger.
Unless the blanket is scratchy, I’ll take the too-big one.
Been there! Hated it! That’s like asking if you’d prefer to have too much water…or too little…when on a long hike. At worst, you can dump the excess, but you can’t very well produce more (ahem!) when you need it.
This feels like a sociological study to see who’s going to vote for the small blanket just to throw off the numbers, even though people will be able to see who voted for the small one.
Other: i would rather sleep with a blanket that was too thin.
I like to be amply covered and detest it when my feet stick out the other end of the blanket. So for me, there are only two types of blankets, just right and too short. If I can be covered from my neck to my feet, it’s the right size. Otherwise it’s too short.
I’m seriously trying to stretch my imagination here to figure out how a blanket could be too big. Maybe we are talking about a blanket that is just so big it can’t even fit in your house? Well that’s no good obviously, but you could always cut a piece of it off and use it if you needed to. Maybe a blanket could be too big for certain regulatory reasons, in which case a user of a too-big blanket will be fined or reprimanded in some way, in which case I might choose the smaller blanket depending on the consequences.
The mind boggles.
I once had a blanket that was about a king sized, when what we had was a double bed. I made tucks in the blanket when I made the bed, because the blanket was too big to fit on the bed…but at night, the blanket was NOT too big. Especially since the heating was lousy in that first apartment.
I like a big blanket that I can get all wrapped up in. Too small is no use to me at all. I needs my snuggles 
Or “too much Nutella”.
Worst answer ever.
There were times I had to sleep with nothing between me and the ground but a thin local girl.
Toobigness is a quality that applies to many things, such as governments, egos, and angsty birds…but not blankets.
This!
Too big. I just hate being cold.