Farther you go, more easy it is. That was not solved. For Tactician mode is even more obvious because of more enemies and more XP. Final battle is a joke again.
Take the Lone Wolf will get more difficulty especialy now when glass canon is not allowed with LW. However, I would not say that difficuly will be consistent.
More difficulty you can get by take all the useless talents. Check here :
http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=574464#Post574464Which makes your tune crippled. Also avoid usage of wands, dual-wield or spells generally.
You would make a party of two melee lone wolfs with all those shitty talents and keep intelligence at 5. That is something.