ExceptIf you have internet then use that with Freely for freeview and give up on aerial is another option.
I wouldn't spend any money on fixing cables ect if the the signal will be switched off in the next 10 years.
1.) that means swapping out what could be a perfectly good TV for a Freely model since there isn't yet a Freely box
2.) not all the terrestrial channels are available via streaming yet
3.) the writing is on the wall that streaming will include mandatory adverts unless you pay a premium. Sky streaming (Glass and Stream) and Amazon Prime do this right now. It's only a matter of time before the rest follow suit
Ten years is a long time, and things will change. The channel selection will improve on streaming and Freely. Fast broadband access continues to roll out across the country. Broadband pricing is increasing in general, but that leaves out some detail. The cost of packages at bleeding edge speeds remains high, and that drags up the averages, the ISPs are also looking to pull more profit out of the 'fast enough' crowd. Despite the increased access to fibre and the speeds it offers, the broadband price trend is still upwards.
For someone who isn't already a broadband subscriber, the cost of entry versus the value it provides is a poor deal. The cost of replacing an aerial and cable might come to £150. Compare that to buying a new TV and ten year's worth of BB subs.
Last time I looked, the TVs were all low rent sets. Would I really want to junk a perfectly good £1,000 55" OLED and replace it with a £330 55" Bush, then shell out £3,000 in BB subs over the next 10 years?

