I am ignoring the overall art work and asking about the time beyond that just a very rough idea

You can't really put a time on that.

It all depends on the shapes and level of detail you want in the map, and the experience and skill you already have in mapmaking.

Making a 10x10 grid of squares is a lot faster then making a proper map with 100 territories.

If your goal is speed, and you know what you are doing, you could make a decent 100 territory map in a few days.

https://www.warzone.com/SinglePlayer?PreviewMap=88984
This took four days, maybe 12 hours

https://www.warzone.com/SinglePlayer?PreviewMap=86906
This has taken several weeks so far, maybe 40 hours

Both of those are more than 100 territories, but its all I've got to help

For me, it took 40 days to make an 1135 territory map

1135 territories / 40 days = 28.375 territories / day

100 territories / 28.375 territories / day = ~3.524 days

I have over a dozen map projects and I procrastinate all of them for months at a time. I takes me about six months to make one map nowadays lmao.

For 100 territories, assume one afternoon to plan the layout of the territories and bonuses, one afternoon to draw it in Inkscape, one afternoon to process it in Warzone, and one afternoon to finalize and test it. If you're unsure about how you'll go about a step, double the time. If you want to get fancy, double it again. Keep doubling for each additional level of artistic fanciness or pedantic attention to detail. If you're procrastinating on this instead of using it to procrastinate on something else, multiply by a factor of ten.

https://www.warzone.com/Map/39159-Serbia-Strategic I made, tested and released this map in 4 days. Had nothing better to do that week, so I worked on it about 6-8 hours a day. It is 130ish territories, has quite good artwork, has a unique bonus system, and required tracing from real maps. So for a simpler, smaller and fictional map, it would take me around 16 hours? Am relatively experienced with Inkscape and use lots of little tricks to save time, so maybe it would take a newbie 24 hours?

So about 30 a day

not necessarily. depends on how much time you spend on it, how experienced you are.

If you spend an hour on it, and depending on how you strategize for example, ninja nic makes his svg then comes to warzone. i do it all at once so I'm not bored with one and have to do the next. Territory-making, bonuses, naming territories. I do it all at once. Helps "visualize" it and you can watch it come together.

I upload it to Warzone periodically, but I don't name territories, add bonuses, etc until I am done with the svg because its way easier to make edits that way.