OP wrote:
"1) Internet Recovery (command R) - I was able to get to the "macOS Utilities""
That IS NOT "internet recovery".
It IS "the recovery partition".
THEY ARE NOT THE SAME THING.
You said you have a tm backup, is that right?
So... it doesn't matter if you "wipe" the MBP, right...?
Here's how to erase the drive using INTERNET recovery (and then how to restore the OS).
WARNING WARNING WARNING
Doing this will WIPE OUT anything that is on the internal drive !!!
PRINT OUT THIS MSG, and keep it beside you as you progress.
1. Power down, all the way off.
2. Press the power on button and IMMEDIATELY hold down:
Command-OPTION-R
You will need your wifi password.
The internet utilities take a while to load -- BE PATIENT.
3. When you get to the utilities menu, open disk utility.
4. VERY IMPORTANT: Go to the disk utility "view" menu and choose "show all devices".
(If there is no "view" menu, just proceed to step 5 ... but if there is, you MUST choose "show all devices")
5. Look at "the list on the left". The TOPMOST item should be the physical drive inside the MPB.
6. Click on the physical drive and then click "erase".
7. If you are going to install High Sierra or earlier, erase to "Mac OS extended with journaling enabled, GUID partition format".
If you are going to install Mojave or later, erase to "APFS, GUID partition format".
8. When the erase is done, quit disk utility. The drive is now completely "empty".
9. Open the OS installer and start "clicking through". The Mac will restart one or more times, and the screen may go black for a minute or two with no indications otherwise. Just be patient.
10. If the install is successful, you should see the initial setup screen (choose your language).
At this point, you need to decide what to do next.
If all you want to do is present it to the new owner, just QUIT the installer RIGHT NOW. Or press and hold the power-on button until the MBP shuts off.
That way, the new owner will open it, boot it, and it will offer a setup -- just as if it were "new".
OR...
You can continue through setup, and when setup assistant asks if you wish to restore your data, connect the tm backup and let setup assistant use that.