The one thing that has me worried atm is that has been a while since we have had a significant Ukrainian positive movement on the fronts. As far as I can tell.
Now, that might VERY well be due to deliberate strategic decisions of just hanging on the ropes over winter and let the Russians punch themselves tired.
Still has me somewhat worried that the Russians with their more concentrated strategy of pushing flesh at the dam until it breaks might have found a way to prevent the Ukrainians from overloading the Ukrainian ability to cover the front AND maintain offensive capabilities.

At which point it becomes speculation about the sustainability of the Russian strategy.

But I sincerely hope that it is just me being overly worried. And that they new NATO hardware arrives sooner rather than later.