Wordpress和Woocommerce：在导入到生产之前合并数据

I have an issue, and quite a big one I guess. Let me state it;

I have a website on production, running with Wordpress & Woocommerce. The website is running ok, get orders and new users. Website is configured with custom theme named X, and it's been like this for 2 years now.

Now we are in 2017, and I want to change my theme, and make a custom theme named Y. So I will work on it for, let's say, 2 weeks.

Here is my process:

1. Dump Prod, and set up Developement Environment (Files and DB)
2. Create a custom rule in .htaccess to get images from production, so you can empty the /uploads folder
3. Set up Github. Start working and developing features.

Then after 2 weeks, my website is done. I want to put it live. But, meh, there were orders and new clients, so how can I pass this to developement website, and then import to production?

I'm seeking for help, maybe there is a dumb thing I didn't thought about.

I've went through the Plugin WP Migrate DB Pro, useless for this.

I've heard of MergeBot, but it's still in beta, and not woocommerce friendly.

Long story short, HELP!

Thanks