Critical requirement for sizing images in HTML email; Outlook ignores IMG CSS height and width

So Outlook messed me up again. We just created an email that went out to donors with a large image with text as the centerpiece. I set the IMG to use the standard responsive CSS, so that it will look great no matter what the device size.

<img style="width: 100%; height: auto;" />

What I forgot is that Outlook ignores that CSS, and absent any old school height and width attributes, it uses the native size at 72 dpi. And we want to use at least a 144 dpi because of higher resolution screens. So here's what I should have used:

<img style="width: 100%; height: auto;" height="875" width="620" />

It all really boils down to: I hate Outlook.