Cannot install Boot Camp - Start up disk does not have enough space!?

Hi,

wonder if someone might be able to help me, as i'm trying to install Boot Camp and cannot get any further than the first step!

I have a late 2016 Macbook Pro Retina, 2.9Ghz i7 with a 2Tb flash SSD and 16Gb Memory. I'm also running High Sierra 10.13.4 and have around 800Gb space left on my SSD.

Using the Boot Camp Assistant, i'm looking to install Windows 10, however when I try and progress the Boot Camp Assistant I get the following error:

I know I have 800Gb+ of space, however I get this message. Looking at the information I can find online (which is to do with High Sierra rather than an older version), I can see that this maybe down to 2 factors:

1. That I use Time Machine for my back up solution and this seems to 'reserve' space.

2. That the drive is formatted using Apples APFS format.

I guess my first question is whether it is indeed one of these points which is stopping the Boot Camp Assistant from doing its job? The second, and most important question is, how do I get round this please?

I booted into the Disk Utilities and tried to create a partition myself, however it talks about 'containers' as well as 'volumes', and as I use this laptop for work, I really don't want to muck up anything.

I hope someone out there can help and steer me the right direction please.