Gotta admit that the concept of emergency power for the house makes it tempting. The Prince of Darkness (PG&E) makes such thinking a necessity in this day and age.
edit: the intended implication of the last sentence is that it costs a good chunk of money, not that it's a bad vehicle.
From all accounts, the F150 EV looks like kind of a good deal in terms of electric cars. What the reality on the ground will be is a different matter. Personally, I have zero need for a car and a fair amount of need for a pickup.
Truth is, it's hard to justify any new car, but then again that's always been true.
For those in PSPS (public safety power shutoff) areas, due to both the reasonably predictable timing and duration, probably the best way to go is a combination of a larger portable inverter generator (in order to avoid the constant roaring) and an interlock to feed the house.