FBW
I did my instrument training at Oxford - also non-radar - if the conditions were IMC, we would generally have to hold, regardless of training requirements, as they can only have one IFR aircraft in the procedure at a time (hence we used to cancel IFR as soon as we broke cloud on the procedure).
I have also had to hold at Cranfield and Gloucester in IMC for similar reasons.
Any radar-equipped airfield, as you say, will tend to just vector you onto the approach rather than make you sit in the hold.