Effect on benefits if moving to UC/PIP area?

Hi all,

If anyone can help with the following, it would be appreciated.

I currently live in postcode area "CM" and receive ESA (support group), DLA (lower rate mob + mid rate care) + Housing Benefit.

If I move to an area where Universal Credit and PIP have been rolled out, will I retain the existing "old" benefits or be forced to apply for UC/PIP? If existing benefits are retained, how long is it likely to be before being forced to change to the new benefits?

This matters because, even if I am able to retain UC and PIP (I don't take that for granted), I will lose the Severe Disability Premium of £61.85 which, to me, makes a huge difference - especially if Housing Costs under UC won't fully cover the rent at the new property.

In case it's of relevance, any move is likely to be to the North of England or even Scotland. The reason(s) for wanting to move are primarily to find an area where NHS services will give me a fighting chance to recover my health. Unfortunately, the NHS services available in my current location have been so appalling, the failures have positively damaged my health and the realistic prospects of recovery are zero (a complaint is now with the Ombudsman but, even if the outcome is in my favour, it won't change the service(s) available to me). In short, if I don't move, I am stuck with no chance of my life moving forward.