The cable length has no effect on the splitter itself. A 2-way splitter will divide the signal strength by about 3db (50% of the signal gets routed to each o/p port.).
If your cable length is excessively long, a splitter may drop the signal to un-useable levels which in that case you need a line amp.
A 4-way splitter will drop your signal level by about 10db or 10x on each of the o/p ports.
Most televisions can handle this drop in signal level via a built in cct called the AGC (automatic gain control) but if your marginal in the upper frequencies to start with, the AGC may not be able to compensate.
I am so happy I cut the satellite/cable about 10-15 years ago and the only thing I miss is the specialty channels.
Of course, I live near the Canada/US border and off-air, I get NBC,ABC,CBS, PBS & Fox from my American neighbours plus all the Canadian major networks CBC, CTV 1 & 2, Global, TVO, Omni 1&2 and a host of others as well.
High gain, deep fringe antenna's do need to be pointed at the transmitter site however to get the maximum signal so a rotor to point the antenna is necessary and can be a pain if your just channel surfing.
The height of your antenna can play a huge factor also in your ability to receive stations from farther away with a MATV system (what your thinking about). I have a 40' tower and a RF signal booster along with about 10' of masting so I'm about 50' from the ground which is a really good height. I can get tv stations from over 100 miles away.