Trying to Create a Video of an Audiobook

Hi all, I'm an author and I'm trying to create an audiobook to upload to YouTube. 

All I want is one static image, and the audio file under it. The book is 15+ hours long. I've compiled all the audio into one file. It is over 1GB, if that matters. The audio is an MP3 file. 

I launch PP, select the image and the audio to import and it does import both. But it will only allow me to drag the image to the timeline. I think the audio might be too long? Is this true? Or am I missing some step somewhere?