You could always treat Lone Wolf like a New Order Grand Master Bk13+.
Re-roll your stats as per GM rules:
CS = 25+Random Number.
EP = 30+Random Number.
HOWEVER, Curing only provides a MAXIMUM of 10EP healed through numbered sections without combat and you LOSE the Archmaster's Battleheal +20EP once every 100 days, the Deliverence +20EP every 20 Days works as normal once learnt.
Psi-surge offers no bonus, Mindblast gives +4CS Bonus.
Weaponskill and Weaponmastery provide no CS bonuses when armed, it could be argued that this is in part the new, higher Initial CS.
Keep all your equipment from Books 1-12 and use permitted Special Items - Sommerswerd, etc.
Huntmastery - no need to eat a Meal in the wild, your call as to whether you can hunt or not Bks 13+ without Grand Huntmastery. I always think Grand Huntmastery causes physical improvements so that Lone Wolf can get greater sustinence from food and therefore not need to eat as often - so ignoring being asked to eat a Meal in a situation where there is no food available implies the GM is still full or has eaten recently behind the scenes/is able to keep going long enough to get into a hunting situation without meriting penalty. I'd say Huntmastery doesn't work indoors but does work in any natural setting, including wasteland & underground caves, etc. Grand Huntmastery of course works anywhere.
Yes it is possible for a lower EP score but then you could be considered out of practise, focusing on Monastery duties and getting older (even if it is only 1 year every 4!).
That seems pretty balanced, haven't playtested it - good excuse to!
N.B. Alternative as Old Order GM Lone Wolf - retain CS & EP from book 12 (Initial + Lore Circles). Curing +1EP/section without Combat (unlimited), Battleheal +20EP/100 days {if EP 6 or less}, Psi-surge +6CS -1EP/round {unless EP = 4}, Weaponmastery +4CS Any Weapon. Plus all permitted equipment too.