We had a new concrete driveway put in 8 months ago in May. It now has risen 1 inch where the driveway meets the garage floor. Also there is some flaking as well. We have had a extremely cold winter. What could have caused the concrete to "rise"? Thanks

"Frost heaves"
Water in the soil freezes and expands, and it's strong enough to lift concrete and even break it.
It means you didn't have a proper ground preparation, proper and deep enough layers of gravel and sand, thick enough concrete with rebar, and sealer after it cured.
The flaking is efflorescence, caused by minerals in the moisture reacting to the minerals in the concrete.
The contractor is at fault.

Flaking may be spalling. Look that up on Google. If you are very lucky, the driveway may settle after warming up. Not enough compaction and insufficient gravel under the slab is the reason.