Not all cable is the same, and RG6 has no consistent specification. The term is now used as an impressive sounding catchall for 75 ohm coax but says nothing about the all important shielding characteristics. Buying an unsuitable RG6 cable can result in interference on your own connection and possibly your neighbours as well, due to inadequate shielding, because cable internet uses a much wider frequency range than TV or satellite, and is therefore more susceptible to noise ingress. And if it's a notable change in length, there's a modest risk that the power levels will be out due to increased attenuation. Third party cable supplier claims of "Virgin Media compatible" should be regarded as meaningless - many use cheap cable because they themselves believe that all coax is the same.
Do yourself a favour, book a flat rate £25 non-fault call out charge, and the VM technician will replace the cable, move the hub wherever you want, and check the power levels and performance remain OK.