There is no such thing as being over powered. Higher levels just mean that you will have less trouble with battles. And at level 56, you're not at a high level anyway. I didn't even start Wintertusk with my Ice wizard until level 58 or so, after I completed Dragonspyre and a good portion of Celestia.
When I did Dragonspyre I was actually above level 60 like 62. If you do all the side quests and dungeons then you would be this level. It even let me do Waterworks while in Dragonsprye and it made it easy on me.