bathroom redo

[B Hall]

I have a one-level ranch with 1.5 bathrooms. The main bath is small (just room for toilet, sink and tub) with no windows and backs up to master half-bath also small with a window. Master has toilet and small vanity. The main bath needs to be redone - pipes leaking floor retiled, etc. Is it better to just redo the main bath or open up to half-bath and make one large nice bath with walk-in shower? How important are the extra half-bath and having a tub rather than shower? Thanks so much!