Is it still possible to host a CSGO lan party without internet access

You can fix the error you where first having (before appending the IP bind) by running those commands:

cd ~/gmodds
echo "4020" > steam_appid.txt

Remove

+ip 192.168.xx.xx

from your command line since the errors in your second log come from that command.

After it shows

Connection to Steam servers successful.
   Public IP is ----------.

Your friends should try to directly connect to that IP instead of trying to find it in the server list. Sometimes Servers do not show up there, but are still connectable.

If you are determined, you can use this guide to find out more about the necessary things to be done to get listed.

The most important step, according to the guide, is to set your server location in the server.cfg. By default, it is set to -1, which would not list it.

Possible values are:

-1: Do not list server (also occurs when you do not set a value!)
0: East Coast USA.
1: West Coast USA.
2: South American Continent.
3: Europe.
4: Asia.
5: Australia.
6: Middle East.
7: Africa.
255: International / other location

This does not prevent anyone to connect to your server from a different region than the selected, it is only used for the filter.

There is no reason you could not do this. Just a bit of fiddling with some Console commands.

The best route I'd say but may require some knowledge of steam console commands is to use a Dedicated server.

https://developer.valvesoftware.com/wiki/Counter-Strike:_Global_Offensive_Dedicated_Servers

You can host a server and provided you open the approproiate ports on the firewall your friend can join. You need only set a password to the server and boom. Private server for you both.

Join the server and then add some bots!

To add bots you can either do this in-game via "developers console" or use the console on the Dedicated Server program.

Can look messy but it is actually rather simple to do bots.

"bot_quota_mode"     "fill"
"bot_defer_to_human_items"   "1"
"bot_defer_to_human_goals"   "0"
"bot_difficulty"     "1"
"bot_dont_shoot"     "0"
"bot_chatter"        "normal"
"bot_autodifficulty_threshold_low" "-2.0"  // Value between -20.0 and 20.0 (Amount below avg human contribution score, below which a bot should raise its difficulty)
"bot_autodifficulty_threshold_high"  "0.0" // Value between -20.0 and 20.0 (Amount above avg human contribution score, above which a bot should lower its difficulty)

Again all the above is listed on the site i linked above. Hope this helps!