I have the same problem. I upgraded my very new iPad to iOS 6... Misery! Big mistake on my end, I lost 50% of the value I get from my iPad because of the very very poor maps.
The only ways I found at the moment:
A - I'm using Google map on Safari
B - I won't upgrade my iPhone 4 so I can still use google maps on it
C - I'll try to re-initialize my iPad, I hope that it reverts to iOS 5
D - I may consider joining a class action since that's the only way Apple may listen
E I may consider the next Surface Tablet with Window 8 since this becomes finaly a real PC on a tablet, not like the iPad on which your Numbers, Pages and Keynotes docs aren't fully compatible with the Desktop version
Very very poor move from Apple, you guys need to react!