Some interesting info/advice from Cooke when emailed them:

"A mature Pakistan would probably survive into zone 7 but the new growth is so soft that we have started recommending it to zone 9 since it freezes so easily when soft. Once it makes it past the first year. It is harder and handles more cold (after all it grows in Pakistan � not the kindest weather location). I do not believe the Pakistan has any secondary or tertiary eyes like some Mulberries have which allow a second and sometimes third recovery from freeze. Since it is budded about 3" from the ground, you might consider looking for any buds left on the trunk (even lower trunk) and if there are any, cut the tree back to above the first eye you find. We even make bush form mulberries with the first one to three buds above the ground (Persian and Black Beauty). If you can find a bud, train it up straight and it will grow out of its slight crook in a few years."

Not sure if i have any initial buds left if that is true about Pakistan not having secondary or tertiary eyes ... Guess I shall buy again from Bay next year and keep it potted inside by a large window till frost is past.

Coldest recorded temperature in Islamabad, where that variety originated, is 28F - not really all that cold; so, their comment about it is BS.
I've had "Pakistan" here in zone 6, on two occasions. First time, I planted it with the graft union below ground level(as recommended by a mulberry expert), so that when(not if) it froze back(which it did EVERY winter), it could re-grow from tissue above the graft union. After 3-4 years of total kill-back, and no fruit, I dug it up and intended to send it to my dad, on the zone 7/8 interface, but misplaced it somewhere.
Later, I got scions and 'high-worked' "Pakistan" about 7 ft up in the canopy of a well-branched young M.albaXrubra hybrid. It survived two years before it froze out completely.
I wouldn't even bother with it outdoors in zone 6 or colder, maybe not even zone 7. Illinois Everbearing, David Smith Everbearing, Kokuso(probably not M.nigra), Korean, etc. are probably better choices for outdoor survival.

Could you keep i in a large pot for 2-3 years. Let it stay outside to get some cold & harden off, then bring it in.
You could keep it indoors until last Spring frost.
After 3 years it would have old hard wood & be better able to stand up to the freezing.
Many person do this with Fig trees.

k thanks guys.
i was debating putting in a large pot for a while if it survives and bring in garage, but I may move onto another one. my small shed was already filled with a few figs this winter :).
Seems like everyone has Illinois Everbearing, maybe i'll just do that.

monk,
I've had IE, Collier, Wellington, and a couple of unnamed hybrids, in addition to Pakistan and some other 'tender' varieties that are no longer alive here; IE is the top producer here - but YMMV.
I have a friend in MI who says that IE is just so-so for him, and he sent me cuttings of his own top performer, which he'd purchased as 'Pakistan' - but it wasn't; didn't even perform so-so here - low productivity, short berry, flavor OK.
Was at a fruit/nutgrowers meeting this past weekend, and one of the guys, a grower in southern IN, was telling me that he's pulled out his IE trees in favor of "Korean", "David Smith", and "Lawson Dawson".

Hey lucky_p,
Where are you finding the varieties "David Smith", and "Lawson Dawson" (lol, I like the last one's name).
It would be interesting to find a mulberry that has some sort of 'tart' flavor that i heard the Persian Black/Moris Nigra has.

So googled Cooke's Pakistan and saw this thread of mine... Just wanted to update it so other people know if this variety survives... My Cooke's Pakistan still has its green leaves as of Nov 6th (even with our OctoSnow). Leaves are slowly turning yellow and falling off past week ... I had assumed it wouldn't like the cold and would have gone dormant before the Persian bush-form Mulberry since the Persian one broken dormancy in Spring with almost all its buds, but the Pakistan broke with the lowest 1 bud out of 50 (rest had rotted off) ... but that 1 bud grow into a nice branch and still has leaves on it (Note: both broke Dormancy May 10th)... The Persian started going into dormancy in early September. Interesting. Will update thread in Spring to see if both survive the winter. Will protect both trees.