Some sites are going to be a problem because they very stubbornly cling to the most logical language for your current IP address. Others may have a better mechanism for overriding that.

For the hotel's own website, assuming you are staying there, I would ask them what their trick is.

If you use any add-ons that block page content (e.g., ad blocker, tracking blocker, script blocker...), try making an exception to ensure that those add-ons are not creating this problem.

Generally speaking, the most reliable workaround is to use a VPN that sends your requests through a router in the U.S. That may be difficult to set up when you are having browser challenges, but for future reference:

The Best VPN Services of 2017 | PCMag.com

You can try these steps in case of issues with web pages:

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

Clear the cache and remove the cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Clear the cache":

• Firefox/Options/Preferences -> Advanced -> Network -> Cached Web Content: "Clear Now"

"Remove the cookies" from websites that cause problems.

• Firefox/Options/Preferences -> Privacy -> "Use custom settings for history" -> Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

I was very well written and easy to follow, but I still cannot get to the English language (:

Does this link work?

• https://www.ihg.com/holidayinn/hotels/us/en/reservation

You are my hero!!