In fact, it will be less than halved to each output as all splitters have a small inherent loss.It will be halved, get a powered splitter.
I would definitely use a power booster. I use one for 4 sets with longish runs of coax from an aerial in the loft with no problems with freeview reception. The other thing is, don't skimp on coax quality use the best available.If I fit a splitter to run 2 tv's off one aerial is the signal halfed to each or will both sets get the maximum signal.