Your holiday sins need to be indulged and you know it!
A training program I wanted to try for a long time is Convict Conditioning by Paul Wade. It is very popular with “calisthenicists” and known to be very healthy for joints and tendons.
I could not find any sheet to track my progress with so I just created my own. It includes links to videos depicting those exercises because I keep forgetting what "Flat Frog Leg Raises" are. Find my free Progression-Sheet here.