I suppose it depends on the room and where the Sky cables come in (but I believe they are extendible):
So you could either extend the Sky Q cables or get longer HDMI cables (and worry about hiding the cables) but there is a finite limit to HDMI length because it will degrade over distance. Some cables claim to be able to get as far as 30m but that's dependent on the quality of the cable. Boosters may be available. The Sky Q cables from the LNB could be replaced and can be quite lengthy (bear in mind some properties you have the box in the front room and the dish on a wall with the cable running either over the roof or around the side) so that could be another option.
I feel converting things back and forth between various standards is going to get complicated and messy.