We have some MYOG UL quilts which started life as UL SBs, but then got converted to quilts. They started life at 550 g each (300 g down, 250 g shell), and were really meant just for summer use. However, we kept pushing them into late Autumn, and ended up using them at -7 C. We were OK at that temperature with Cocoons on, and the two quilts layered on top of each other. Just. Took some managing of the two layers. :-) I have since added about 100 g of down to each one to handle colder conditions.
But for winter/snow use I decided to make up an overquilt to go over these summer quilts. That's what I am talking about here. I'm 64, so yes, we do both turn over a few times in the night - at about 10% wakefulness.
Now, the secret to happy quilting in my humble opinion is to have a genuine footbox on the quilt. That applies to both the summer quilts and the winter overquilt. The summer footboxes are just like the bottom end of an ordinary SB. Not surprising, as that's how they started life. The winter footbox is actually a full-width single layer of UL fabric under the bottom 1/3rd of the quilt.
Why? Because while you can control the top end of the quilt easily, your feet can escape from under, and fixing that up in the middle of the night is a full sit-up job. But with a footbox the lower end of the quilts stay totally under control, and that does tend to keep the top end under control as well.
So, Sue gets under her quilt while I finish off tidying up. Then I pull my quilt over me. In summer, that's it. In winter in the snow I then arrange the overquilt at our feet, with the footbox going under us and just under the botom end of our airmats too, and then I pull it up over the two of us. And it stays there on top of us.
No, I do not tuck it in at the edges at all. That width is quite enough to leave an adequate amount flopped on the ground at both sides. It could even be a bit narrower maybe and still work just fine.
You mentioned that 'she's a blanket hog' - a well known happening. My wife clutches a bit as well. But if I keep her warm she relaxes and we spend a happy and warm night. If it's a warm night I just push the overquilt down off us a bit - but it is still there if we need it.
Does this help?