Squarespace to WordPress

I was wondering if anyone can share some ideas on how to successfully migrate a large website from Squarespace to WordPress?

Steps I've already taken.

• I've downloaded the XML file from Squarespace
• I've installed the WordPress Importer Plugin
• I've imported the XML file into my local dev WordPress install
• I've installed the Import External Images Plugin

The issue I'm having is that the WordPress Importer Plugin fails to download some images from the XML file.

Also the Import External Images Plugin is not able to recognize some of the images from the Squarespace XML file.

The pictures show but are hotlinked to Squarespace which means once I upload to production environment and cancel the squarespace account, the images will be broken.

What I'm trying to accomplish is to get all the images properly uploaded to my local dev site and then migrate to production site.

I've Googled this question with no good solution so far. Any Ideas? Thanks

In my experience, we've needed to literally open every single page and post to get the import external images plugin to run. Additionally, we have had to limit how many images it imports at once to <50 or else it times out. Basically, I've had to do this incrementally to fully import images properly when migrating from Squarespace to WordPress. It's quite tedious, but doable. 

Interested to know why you are shifting over to Wordpress?  Is it the range of plugins available?  I've a personal blog using WP and find it good also.