I would hate to admit to being outmaneuvered, but I will say two things: 1) Lady Luck was indeed unkind for the first 5 rounds or so. 2) I did expend too great an effort trying to make the bear tank "work". Should have tried to get something else going while he distracted her.
Things I learned:
1) If you do go this route, let the bear take care of himself. No need to get greedy and cast Bear's Strength or Battle Fury or other similar spells on him. He's big enough as is, so focus on something else.
2) Do NOT go solo big creature against a Priestess. She has way too much crowd control, and you will spend most of that creatures actions rolling against dazes or removing stuns. Against the Priestess, I'd take quantity over quality.
3) Try to avoid getting down below 5 mana if you don't have a spawnpoint out. After I got my Bear out, I realized I would be very mana limited for a while, especially if I tried to cast two spells a round. As a result, it took me far too long to get a spawnpoint out, and I just couldn't catch up to my opponent in terms of creature strength.
Perhaps one of you better, more experienced players will try this and make it work, but I'm going to stay away from the Super Grizzly opener for a while.