It depends entirely on your needs and current health state. If 20/40/40 seems attainable and sustainable to you, then go for it. The nice thing about Paleo, is that it doesn't dictate what your macros should be, which allows you to find what works for you.

You probably don't need quite so much protein, though. You only need around 1g per pound of lean body mass. For women, this generally works out to around 100g, or roughly 25% of calories. That said, if you have a plan in place that includes that much protein and you want to stick with it, that's okay, too. Protein isn't a fuel macro, though, so remember to not treat it as such.

From there, allot your carbs and fat as you see fit, so long as you get at least .3g per pound of total body weight from fat (for which your 40% is more than adequate). If you find yourself hungry all the time and have trouble sticking to only your calorie allotment, then increase fats and decrease carbs until you find yourself able to self-regulate. If you're finding yourself so not hungry that you have issues eating a reasonable amount of food, let alone your getting up to your calorie allotment, then reduce fats and increase carbs until you find your balance.

Also, as long as you're providing your body with enough carbs and/or fat, activity level doesn't particularly matter for macro splits. If you're making a big change from your old habits, it may take a little time for your body to adjust, but the body can still do things using either as primary fuel.

I personally think that fat should be 50% or more... so in your case, the excess protein could be fat. But if what you are doing is already working and you have no issues with cravings, slow metabolism, or anything else then it's not important to sweat the macros. Your body will likely dictate your best ratio.

I have health problems related to metabolic disorder so my carb macro must always be strictly limited. I aim for about 70% fat, 25% protein, and 5% carb.

I have my goals set at 10% carb, 30% protein and 60% fat. That is ideal for me but I often have flucuations.