How do you use I2C at 5m?

This is My first post to a form, ever!!!

I have a Question that is harder to answer the more I research and find out about it.

What is the reliable distance of a I2C bus line with one or multiple I2C sensors or devices connected to it? (10-30cm total length aint much)

A little background.
I am choosing I2C because I like the simplicity of 4 wires, the availability of sensors/devices using I2C and its commonality of open source code help. I am “Beginner Mode” when it comes to IOT. Hardware is less of a learning curve than is the software side. “chicken or the egg” is a lot like “hardware or software first” I am learning you can’t build one before the other.

I am trying to decide on a semi standardization to my various projects. I want to connect a master box (Arduino Uno) I2C signal to multiple slave I2C boxes (sensors ect.) via RJ45 shielded CAT6 cable. I’d like to know.

What is the best and reliable way to connect I2C components ? (to avoid voltage issues at length, crosstalk, line capacitance ect)

Required length 5m
Id like the option for up to 15m
Greater than 15m I’d just move to serial (I don’t like having to add a extra layer of serial to I2C conversion and I still want to use a RJ45 connector) or just place another Arduino at the other location.

I have included some block diagrams to help illustrate my plan. A lot of my executions need to be weather resistant hardy and are not Permanent. Am I overthinking this or do I need to revamp? like RS485 and conversion board?

I have never used wires more than 50 cm for I2C bus. It was not designed for communication over longer lengths. In standard and fast mode, you can only have a max bus capacitance of 200 pf with resistors. When you increase cable length, it adds up to the bus capacitance. I believe twisted pair would allow you go a bit longer but you'll have to experiment I guess.
Check out these:

For multiple sensors, each sensor needs to have a different address. Most sensors allow only 2 different addresses, so if you have sensors from the same manufacturer and model, you can only have 2 of those on the bus. If you still want more, you need to use a bus multiplexer.

The best way to connect would be not to exceed the bus capacitance limit and use appropriate pull-up resistors.

I2C Range Extender