Around how much land would the testing grounds take up, do you think? The Big Five had plenty of open land for testing though Eastern Europe would need to choose where they detonate their warheads wisely, especially if they don't want to sentpd fallout into their rivers, cities, over the border, or potentially trigger a war by making people think a first strike had occurred.
It is more about brag of doing so. And then it will not have to be a big one, a very small one it will do the trick (in an military shooting range ),it might be possible to get a way with out detonation one,but you must let them know that you have one
Another possibility is to detonate one in space if you have the capability of lunching one
And yes land it will be an issue
And yes it is a very risky undertaking but it might be the only chance,other then a Vietnam like scenario.