Extinct in Six Generations: No.
This post has been getting around a bit and while it's good to have a sense of urgency to White survival, this is just disingenuous doomposting.

Assumptions made:
–White outbreeding at a constant rate.
–White TFR at a constant rate.
–Non TFR at a constant rate.
–Mixed TFR at a constant rate, and above replacement.

When assuming all of those, of course there's an end date.

As Whites shed population from outbreeding and low TFR, it introduces two selective pressures, which Whites who have higher TFR and Whites who are less likely to outbreed, become more representative of Whites in general.
–Outbreeding decreases over time.
–TFR increases over time.

Nons tend to go the route of total fertility collapse given more time. Whites have a TFR floor of mid 1's while Nons drop well below 1.
US mixed-race TFR is also extremely low.
–Non/ Mixed TFR decreases over time.

Ultimately though, if you aren't having a large White family, you contribute to low White TFR.