Just have the time off and have a holiday, that's what holidays are all about IMO.
Relax and enjoy three weeks off, over a lifetime of training will make no difference at all, who cares, who are you competing against??
Let your body fully recover over three weeks, there is no way on the world you would lose strength in three weeks or size for that matter, if anything the opposite would be true, you would be fully recovered and ready and keen to smash it once you get back into every day routine.