Call them, but I doubt they will answer at weekends unless they have an exercise on.
If you don't get an answer then just self announce and go through the MATZ
Keep away from their ATZ as they do have gliding and other things going on.
Lakenheath/Mildenhall will give cover in the area to the NW when Wattisham don't answer, but the controllers will be very laid back Americans so the service is very different.
I don't think there is any food at Elmsett so you will need to arrange transport to a pub.
Old Buckenham does have food on Fri-Sun and so do the gliding club at Tibbenham