If your estimate of the probability of their eventual revival is p, shouldn't you feel (1-p) fraction of grief?

Bwuh. That doesn't seem to add up to normality.

If a loved one who has no intention of ever signing up for life-extension techniques (or suspended animation) departs for a distant country in a final manner with no intention to return or ever contact you again, should you feel 1 grief?

Your system works when one attaches grief to the "currently dead and non-functional" state of a person, but when one attaches it to "mind irrecoverably destroyed such that it will never experience again", things are different. This will vary very dramatically from person to person, AFAIK.