How do you build relationship with skip manager (executive) when you do not have any meetings with them and you are working remotely?
If I do carve out an opportunity, I'm also afraid that my boss might question why I am trying so hard to build a relationship with his/her manager given I have nothing shared to work on with the executive. If there was, I and the executive would be atleast in some common meetings where I would get the opportunity to build relationship and demonstrate impact.
What are you trying to build the relationship for? That should dictate the way in which you interact with the skip level.
People at higher levels don't want to build a relationship for the sake of building a relationship. Instead, you could connect with them for:
When it comes to skip-level meetings, it's generally more of a case of them coming to you vs. you going to them. This is especially the case if they're firmly an executive level (i.e. Senior Director and above). Senior engineers in particular generally won't have a close relationship with their skip - That starts happening more at Staff.
You just want to be prepared if your skip reaches out to you for a 1 on 1. Here's a good video talking about how to get the most value from those meetings: How To Effectively Leverage Skip Level 1:1s