Get enterprises in every town and go for quality troops. If you made your character and party right, by now you should be able to train Adventurers quite easily, and have enough Training skill within party to slowly train up Hero Adventurers. Mix in various high level troops from other sources, and you'll have party good enough to handle weaker unique spawns like Kodan or Heinrych, or lords if you joined any faction. Keep building up your renown and character by picking some daring fights and winning tournaments.
If you have really small party, you can get a lot of renown by soloing stuff. Certain parties, while seemingly intimidating, can actually be quite possible to solo, if you know the tactics. Pack a good, decently fast but not entirely weak horse-leather draped horse served me well IIRC in those stages-good lance, long slashing melee weapon, couple of shields and in inventory, ranged weapon and ammo to switch instead of shields when necessary. Vanskerries are quite easy to solo as long as they didn't recruit crossbowmen or ranged cavalry from prisoners-just run around to exhaust their throwing weapons, use the melee weapon to dehorse that bit of cavalry they have, and then it's lance time. Similar method can be used on Knights of the Dawn parties.
It is possible to solo even Alaric this way, but it might take a few hours.