We are planning a trip to the Trans-Carpathian Oblast', perhaps in May (to include Uzhgorod and Mukachevo), and are interested in details regarding timeframes and difficulties crossing the border to also visit extreme eastern Slovakia to see my father's village (in the Carpatho-Russian section of northeast Slovakia near the border).
We visited Czechoslovakia in 1974 and were able to go up to, but not over, the border with the USSR because of visa requirements, so have never seen Uzhgorod even though it was just over the hill.
When my brother visited Slovakia in the late 1990s, he indicated that he and a friend drove into Ukraine relatively easily in a private auto, but then for bureaucratic and security reasons, it took 12 hours to get back from Ukraine to Slovakia because the border guards were very restrictive. (I don't know for which country.)
Are things any better now? We would hope to take a bus or local train from Uzhgorod to Michalovcy, and I know my way from there, but it would be a shame to have to waste half a day at the border each way, just because there happens to be a border going across what is a 20-mile trip.