You have already tried this one, you know. The polling has been done, and most Conservative Leave voters in England would see Northern Ireland go for the sake of Brexit, a choice that now presents itself starkly. At least half of Labour Leave voters never wanted Northern Ireland in the first place.
If people in the rest of the United Kingdom still think of themselves as having an enemy in Northern Ireland, then it is the billion pounders of the DUP. You need to give this up. You are not reaching anyone at all with it. You have already tried it once, and that resulted in the hung Parliament that has probably doomed Northern Ireland in the fairly near future.