I really hate the idea of the last village cannot be destroyed. The account owner cannot does anything, neither do his/her neighbors. Oh, I almost forget, they can throw some $$$ to buy that account and delete it later. WW villages may be the exception.
My suggestion: Once the village is destroyed, 3 settlers will be spawned (automatically) and travel to 0|0 (hello MH, yes it is your home) at settler's speed (or maybe slower). Then, the owner can choose to send the settlers anywhere like normal. If the village has an artifact, a natar village will be spawn (with/without troops, this needs more thinking) and containing that artifact.
Can it be abused? Yes, but no effective. The scenario is 3 ppl rush early cata, destroy all first villages of their teammates. Then their teammates can choose 15c as their 1st village. But I doubt anyone will no it. Attack is only possible after BP. And settlers can be delayed to make it much less effective.
PS: implementing this feature may be tricky, but not impossible.