Arduino relay module distance limitations

I'm completely new to Arduino, but diving in head first. I presently have multiple isolated control boxes of timers and relays controlling a number of things around my home and hobby farm such as outdoor lighting at dusk, automatic feeding of horses 4 times a day, exhaust fans, opening and closing windows in the barn depending on temp and humidity. Well I think it's time I consolidated all these isolated devices into one controller and get with the times...... My first question is the operating distance a relay module can safely operate over 22 ga twisted pair wire. As I am bringing everything back to a central point in my home, my analog experience tells me to calculate voltage drop. I can remotely power each relay board, but the high/low digital signal is where I get lost. I don't know the current, and not sure if it's even relative with a digital signal. So...... I would appreciate any knowledge you can share with me regarding the maximum distance over 22ga twisted pair you can safely operate a relay module. I have one location of a pump, that is 900m away, will it work??? Can this be compared to DSL internet where the modem can be 7 or 8 km's from the exchange equipment and the digital signal is fine???

Love to hear your comments on this and any experience you've had.

You can compute all values, or simply measure or try out with a cable roll under your desk.

For long distances the cables become complex resistors, with the relay and controller port being further complex resistors. That can make computation hard, unless you use a tool for that (like LTSpice) with a precise model of all components.

The digital pins are not powerful enough for driving long cables and relays, and also are subject to electric hazard (shortcuts, lightning...). So you want to add (differential) line drivers and receivers and protection to each line, and proper termination of each twisted pair.

Use opto isolators over the long runs.