According to CNN and the Ukranian Defense Ministry, Russia has at least 127,000 troops massed outside of Ukraine as of January 19, 2022. If Russia does in fact invade, there are questions of
Russian objectives (how limited or extreme the incursion into Ukraine would be)
the stiffness of the Ukrainian opposition
Russian logistical capabilities.
With Kyiv being both the capital of Ukraine and approximately 380 km (240 miles) from the Russian border, reaching the city with ground forces might represent one of the more extreme outcomes in the range of possibilities.