Lets assume that a scientist somehow discovers or observes that there is an asteroid heading towards Earth. They have some time to prepare for this event, say 10 years. The variance in the calculations would be too much to ascertain a specific impact location. The man has worked as a researcher for a London university for most of his life, is intelligent and if he liquidated his assets could potentially free up ~£1M to buy/build/plan for this event. He would want to protect both himself and his immediate family of, say, 10 people in total.
If the asteroid hits the landmass where the scientist is located any attempts to ride it out would surely be doomed to failure (?). If the asteroid hits a land mass a large distance away then survival would surely depend on whether you have enough resources to ride out the ensuing winter. If, as is most likely, the asteroid hits an ocean; one would need to ride out the ensuing megatsunami and the following winter. Potentially, one would need to consider a firestorm; but again it seems to me that attempting to ride something like this out would be futile. What follows below is my assumption of a valid strategy but I would be grateful for any counter points or improvements on this.
It seems to me that the best course of action for our hero would be to attempt to construct a building to survive a megatsunami and then plan to hoard (but also generate) resources to survive the ensuing period of low sunshine. Hero should choose a plot a land in the Scottish Highlands as it is cheap, isolated and elevated. The building must be able to survive a megatsunami. Potentially it could be at an elevation of 500m-800m, but numbers for megatsunamis indicate that up to 2000m is possible. How do we design a building that can ride this out? The building must be able to harvest some form of renewable energy; bearing in mind solar will be severely reduced this must mean wind? One could potentially hoard enough resources to last a year or so, but will need to be self sustaining as potentially the winter could last a decade or so. There must be some form of system to transport himself and his family from London to there since when the impact approaches it is likely that roads will become unusable. There must be some form of hidden entrances/exits and security system as it is likely that many of the people who have worked on this building may become aware of its purpose and seek to hijack the building or force entrance nearer to impact.
Any ideas to flesh out my story would be much appreciated :)