If he is indeed terminally ill, then yes I believe that spurred him on to invade Ukraine. That, and Trump losing the 2020 election. I believe that Trump is a Russian asset and his job was to bust up NATO, render it useless. He was unable to do that during his first term, so I think that Putin was counting on him to finish the job during his second term. When Trump lost the election, Putin had to make a choice whether or not to go ahead with his plans. I think that his illness, whatever it is, was the deciding factor in him going ahead with his plan to invade.