Actually we will do the spell in Thoralinar, sadly I do not have the source to cast that particular spell in Tornilen :/
Taking the status rules into account, you can start moving in WM 5.
So WM 5 you go from Ghorien to Bheline, cast your spells, continue to Rhumannen and then arrive in Tornilen.
In WM 6 you go with my forces into Thoralinar, I cast my spell.
In WM 7 we move from Thoralinar to Chalsedon and end in Ansien.
The reasoning behind this is that Osoerde is not very peaceful right now... and to avoid Osoerde, you really do have to go through the Grey Hills. I imagine it is more fun to go through Thoralinar than Sendouras