A friend of mine freezes his light lagers solid, then thaws before drinking. They are very clean (which he attributes to freezing), but I've never had the frozen/unfrozen versions side by side for comparison. You'll definitely be able to drink it once it's thawed. If you start drinking it before it's totally thawed you might get an interesting first couple of pints, but you won't want to finish the keg I think.
Let us know how it tastes please!