1. Download Ubuntu iso, burn it on DVD
2. Download bitaddress.org html with javascript (
https://github.com/pointbiz/bitaddress.org) and burn it on CD
3. Remove Harddisk of laptop
4. Boot from Ubuntu DVD.
5. Load bitaddress.org local html site from CD.
6. plug in printer
7. print wallets
8. unplug everything from power.
EDIT: put just 10 BTC on one wallet address (better 5 BTC or even better 1 BTC) if practicable! to avoid the damage if a possible but very unlikely collision occur. then rent a bank safe deposit box and you can forget it for 5, 10 or even 20 years.
Switching on wifi for a minute could give me a compromised version of bitaddress with predictable keys?
Yes, I will split them up with 5/10 BTC each.