Elias here with Shopify Support.
There isn’t a way to split one item into two separate packages as our system can’t separate the weight, this would only work if the order has items being fulfilled separately. There are a couple third-party shipping apps that can help with this, I’ve handpicked a couple for you to try out:
If you require technical support with these apps, you can always reach out to the developers directly through the contact information found in the Support section of their app pages.
The alternative method is just as you described, you can create an extra product template for those products. Creating an alternate template is useful if you have different product types, such as pre-orders or contact us, instead of the standard add to cart template.
You can replace the ‘Add to Cart’ with a contact link so customers can reach out to inquire about the product and not simply adding these products to cart and checking out. This will also help reduce the order management for these products so you don’t need to refund orders or follow up with customers regarding their order. Then once you’ve communicated with the customer about the shipping for their order, you can create a draft invoice and send the invoice to your customers.
If you’re not comfortable with coding, our design team could take a look at your theme. Keep in mind that our design team will only be able to support Shopify Themes, not third-party themes. Just reply to the thread here if you would like this done, and I can proceed with the next steps. - Elias
Maybe this would help someone landing on this page.
If you are shipping with FedEx, the FedEx Rates, Labels & Tracking app would be a perfect solution. While creating labels for an order, you can split the order into the number of packages you require. This will split the weight and the price as well. Once this is done, you can easily create FedEx labels for these packages and automate the process.
Thanks so much for recommending Intuitive Shipping! I'm happy to announce that we just launched our third app, Smart Boxing, which would also be a fantastic solution to @overlandsprint's requirements. Since it 'only' does dimensional shipping (my dev team will kill me for saying only lol - it's a very robust system), the entry pricepoint is much more doable for smaller merchants just starting out
Just like Intuitive Shipping, Smart Boxing is free to install and configure, and then merchants get a 14-day free live trial to take it for a real test drive in their store.