Can you refresh a data model

Here's the scenario:

1. I created a data model in Power Pivot - connected to 22 queries, relationships are built out, measures have been added. 
2. I imported that data model into Power BI - everything transferred over correctly. 
3. As I am building out the report in Power BI, I realized that I need to add a few new measures. Easy enough to do in Power BI, but now there is a discrepancy between my Power BI data model and my Power Pivot data model. 
4. Here's my question: Is there a way to "refresh" the data model I already have imported into Power BI? So, if I need a new measure, I can add into Power Pivot first, and then refresh the Power BI report?
5. Otherwise, I am forced to either make the same change twice in both models, or create an entirely new report with the updated Power Pivot model.
6. Yes, I realize that I can "detach" myself from the Power Pivot model and use Power BI, but I plan on adding in several new queries over the next month or so, and don't feel Power BI is equipped to handle the entire ETL and Data modeling process.

Thanks in advance!