-
You can set it to automatically upload but I don't know if it automatically deletes the local file.
Personally I like having all my pictures on my phone so I have an alternative method for creating space. Every so often I'll copy all my photos to my computer and run them through the batch conversion on Irfanview to reduce resolution and jpg quality. This generally results in files that are about 10% of the original size (all originals are stored online) which I copy over the existing files on my phone to recover the space.
If you also need Office then that's a cheap option for cloud storage. Generally costs about £40 a year for Office plus 1TB of storage (or the Home subscription with 6x Office and 6x 1TB for about £60 a year is very cheap if you have a few people using it).