Stretching the browser page to the size you would prefer should reset how the page will be opened from that point on or after you re-open the browser.

If you are aware of any web-page URL's that shrink the web page, then right-click the link to open in new window (or open new browser window before opening the URL.) Close that page when finished with that page.

Does that help?

If I am not understanding your problem properly, please give me more details.