Well. "Without restriction" as long as you remember to go offline while you still are online (for single player games ofc).
Origin cannot be put offline if:
- You don't have any internet connection, and
- You were online the last time you used Origin
Oh, and if Origin sees an internet connection the next time you start it, even if it was put in offline mode the last time you used it, it will go online again regardless (unless they have fixed that since last year, I haven't really checked lately).
Therefore I keep Origin offline most of the time. I made an outward rule in Windows firewall (any firewall should do), blocking origin.exe. If I have to go online I just temporarily disable that rule. It's a little bit of a workaround but has worked great so far. So if you have Origin on say a laptop and are off to a place with no internet connection, you have to do this first if you want to play Origin games.
But if you have say mobile net even if for a short time, you should be good to go to connect Origin just to go offline (unless you wanted to stay online ofc, but that might be pricey on a cell phone).