Daffodils should be planted 6-8" deep for best performance. I don't know if freezing will affect the bulbs, but I suspect it will.

They won't freeze if planted to shallowly...but the bulbs will tend to multiply and make a clump of lots of little bulbs....and not bloom as well.
I would leave them alone this year....but perhaps next summer after they have bloomed and the leaves ripened off, dig and plant deeper....with a little bulb booster in the soil.
Linda C

Freezing won't hurt them if they have roots.

I would leave them alone until the flower display weakens, unless you feel like the extra exercise. When they don't flower so well any more, dig them and thin them out. Plant them deeper if you like. Most daffodils spread vigorously in good soil and will need to be divided regularly to stop them getting too crowded.

Digging to twice the depth of the bulb is to prevent the bulb sitting on top of a hard layer of soil which will collect water around the bulb. My soil is very well-drained and I don't do this, but in some soils it is important. Most daffodils are quite tolerant of heavy soils so I wouldn't worry about this too much.