What I do is to tell the other person that I'll be using this other number and to call me if there's any change of plans.

Edit: I actually have two phone numbers. So the new phone is still at home receiving everything

Is having a second phone number and telling people when to contact you using it really easier than just... not looking at your primary phone?

Not specially hard. And you're comparing different stuff. I'm not using a different phone because it's easier, but because having a smartphone is distracting. It's noticeable, but in case you need a link.

https://www.sacurrent.com/the-daily/archives/2017/06/28/just...

Incredible — the effect was present even when the phone was turned off. I would think that a phone that is off but nearby would be less of a distraction than a phone that is on but in the next room. It would take longer for me to turn on my phone than walk to the next room to get it.