After nearly 6 months of the coax from my 6m/2m/70cm antenna coiled up in another room, I finally got round to connecting it into the new shack, by running it up into the loft and joining to an extra piece of coax I'd put in for a temporary 2m dipole.
It's not perfect - it's 7 metres of RG58 I'm adding, giving up to 3dB loss on 430MHz and 1.5dB on 144MHz, RG58 being what I had handy and easy to wire into a dipole centre.
When I put the GP15 up, I'd left enough spare coax (Westflex W103) to reach out of the room and across the house, but I wouldn't be very popular if I just trailed it along the floor through open doors to reach the shack.
I'll do a direct run of coax some time and get the Comet GP15 down to check it, it's still working fine but it doesn't sit exactly straight so I hope the screw holding it into the tube hasn't snapped (they often do on that kind of antenna).
For HF I'm still using a wire along the gutter, fed with an UnUn and sticking mostly to 10 and 14MHz. The other wire is still up in the back garden but the coax is left coiled up in the old shack.