Running EMT conduit through soffit into attic
OK, I am assuming you are running 15A or 20A circuits for the bathroom and it can be run in 1/2" conduit. 

First you are right to abandon the idea to bend EMT through the soffit and into the attic. Unless you get really lucky the geometry just doesn't work out. Instead you need to either transition from EMT to LFMC, Liquid Flexible Metallic Conduit (Sealtight) and run the it through the opening between the soffit and attic. You could also run the entire circuit in LFMC, but it requires a lot of strapping to make it look neat. I also suggested LFMC because if you use LFNC (Carflex) or Liquid Flexible Nonmetallic Conduit with no metal you may find it exteremly hard to bull wire through it due to the friction of the insulation and interior of the conduit.

You need to have at least a 7/8" (let's just say a 1" or larger) opening to get the conduit through to the attic. How you do it is a good question you can try and push it through. You might be able to fish a wire or fish tape up through the opening. I have found my best success with "fish sticks", found in almost any hardware store. 

Now here is what most people don't want to here. When all else fails you may have to take down some of the soffit panels to install your conduit or cut an opening in it using a small plumping access panel. Either way if done properly neatly it's really not as horrible as it sounds initially. 

Be sure and seal up any exterior holes into the attic since all kinds of inserts and varmints can use them for access.

Good luck.