1st 50 mile

Hey,
I'm looking at a macro-schedule for my first 50 miler in 2018. I have a solid 16 week training plan and am prepping now with various races. This season is a recovery/back to running after a long hiatus season. Feeling good and injury free but as I approach the end of this season and the gap between it and the start of my 50 mile program I am wondering what to do in the interim? Specifically, how do you all train in the "off" season, volume, activities, etc?
Thanks.