I think local restrictions would be an interesting way of containing it, as I’d argue that they seem to have had mixed success throughout the UK’s pandemic.
One of the more successful examples of localised measures we’ve seen in the UK is surge testing being applied to areas with variants of concern; the South Africa variant was causing a similarly concerning situation a few months ago, but the surge testing being applied to areas where the South Africa variant had been logged did seem to really drive down the spread and stop the South Africa variant from spreading out of control. The SA variant could have escalated into a real crisis for the UK had it been allowed to spread unrestricted, what with it having the E484K mutation that can allegedly bypass antibodies (for clarity, the Indian variant doesn’t have E484K, which is why it wasn’t initially designated a VoC), but the excellent surge testing has meant that it’s been little more than a drop in the ocean thus far; there’s still been less than 1,000 cases of it in the UK, and we’re a good few months on from when it first began spreading. Thankfully, surge testing is now being applied in areas where the India variant is more widespread, as well as surge vaccines, so hopefully that might stop it from developing too much.
On the flip side, a less successful version of localised measures was the local lockdown scheme, which later evolved into the tier system, which was utilised during 2020. While I won’t deny that local lockdowns/tiers are both decent concepts that were introduced with good intentions, and I think local lockdowns/the tier system might have worked with a few tweaks, I think the rules were ultimately quite hard to enforce on a regional basis. Short of physically blockading in high risk areas, there’s not really too much you can do to stop traffic in and out of local lockdown areas, and I think that is where the initiative ultimately fell down. I do think this strategy would work with a few tweaks, however, so I wouldn’t exclude it entirely.
Personally, I think localised measures might work in this context, or at least should be tried before resorting to national measures. Currently, the Indian variant is only really widespread in a very small number of areas, and case rises still only seem to be happening in a very isolated context in a small number of regions. The UK’s overall case trend is still very much going downwards, and the hospitalisations & deaths are still falling quite sharply countrywide; I think I even saw that something like 2/3 of local authorities now have little to no COVID, so the regional disparity is now growing stronger. As such, I personally think that localised measures exclusively for hotspots like Bolton are at least worth attempting at the current moment as opposed to national measures.