50a to 30a to 15a - AC issues

My trailer is wired for 50amp service. I only have one AC unit right now, so it's only really in need of 30amp. I have the 25' 50a cord that the RV came with and I just bought a 50' 30a extension cord for situations like when we're at a friends house and need to plug in the AC for the dogs and there isn't an outlet within 25ft. I've used the 50a cable with the 50a to 30a adapter and then the 30a to 15a adapter plugged into the house and it's worked with no issue. I tried to plug in the 50a cable to the 50-30 adapter and then into the 30amp extension cord, then the 30-15a adapter and into the outlet at home and it's causing the circuit to overload. I thought may be the extension cable was too long and it's causing issues, but then I went back to the 50a cable with 50-30 adapter straight into the 30-15a adapter and it kicked off again.

Why would it work fine at one point without the 30a extension cord, not work with the extension cord and then after all that not work without the extension cord the 2nd time?

If I get one of these adapters and go straight to the 30amp 50' cord and to the 30-15a adapter, that should work for me, right?

I've heard 50' is about the max distance you can have before you start having power issues. I just want to be able to adapt in any situation and be able to get power from a proper outlet at home, at a friends house, etc... Basically anywhere there isn't a 50a or 30a outlet. I'll be on a 3 week trip in places where we'll need power and won't have traditional RV park options and I want to be prepared.