First up, fuck that joke about buying your wife a handbag… It’s not funny, it just reinforces gender stereotypes around parenting and it kinda shows you’re probably nowhere near having the mindset to steer this situation into a better place.
If a conversation starts as an argument, it’s never going to be anything less than that.
So, your wife has what sounds like a high pressure 9-5, and then ends up with a whole second “job” on top of that, which knowing kids will basically run from the second she wakes up, until the kid goes to bed. Leaving her with probably a few minutes for herself. (I have vague memories of you mentioning that you’re expecting too, so all that whilst pregnant too?!)
Put yourself in her position. Is that something that you would welcome and look forward to? I’m guessing not. So lets say that her reaction is fair and 7 days of others needs trumping your own isn’t something she will relish and will likely lead to high emotions.
With any high emotion situation, it’s important that you understand what it’s like for the other person and act accordingly as though it were you in that situation.
Putting on my assumption hat, and with the knowledge that discussions around this are starting as arguments, I would guess that she is probably feeling like you don’t understand what a burden this is for her and underplaying it as a necessary part of your life that she just has to accept with no agency for herself. If you can get to a place of understanding/acknowledging the burden and truly seeing how the travel situation affects everyone in your house (and life, as I imagine this has ramifications on your other kid/ex too), then you’ll be in a better place to mitigate the effects of it together.
Given it sounds like travel won’t be going away for you… How do you mitigate the effects of it?
Some suggestions…
First up, insourcing some help. Think of child care as outsourcing, you have to take your kids there, and there is a lot of leg work involved outside of the hours they’re actually there. Look at an actual professional nanny, or a cleaner, or even just a babysitter that can come and help with some care for an hour or two. Lots of people in my area pay for someone to do after school care, eg pick up the kids, look after them for a couple of hours, maybe organise dinner etc etc. If you’re making all the extra money and you’re in the great financial place that you claim to be, this seems like it should be possible for you. There’s no point having nice cars, a bigger house etc if you’re miserable in them.
You need to help organise this though. This isn’t another thing you should add to your Wife’s list of things to organise. She gets veto power of course on who to choose etc and has hiring/firing power, but you need to do the leg work on this as an acknowledgement of it being a situation your job has created.
Secondly, I would suggest ensuring that you do what you can to reduce your work travel. Eg. you’re going somewhere nice? No, you don’t get a day to yourself to look around and soak in the sights, you’re on the first plane possible to get home and you need to force your work to support that. No having the naive admin person booking the cheapest options that extend your time away.
Thirdly, build some networks where you live. Maybe pause some travel for a bit if you can and cultivate some local parent friends through school, childcare whatever. Parent friends are great, if you’re away, ideally your wife should have some people that she can reach out to, that could have her over for dinner, lend a hand, whatever.
I could go on, but I’m supposed to be working.
In summary though, there’s no magic fixes for things like this. You need to talk things over, work out her fears, concerns, sticking points. Work through them, figure out constraints (eg. I will only travel 5 days a month. I will only travel for the next 2 years and then will take a break from it for 12 months etc).
Also, if she is pregnant, she might also be fearful about how these periods of travel will impact her when there is another baby on the scene.