Timeframe is really hard to say. I'm very surpirsed that ANY U.S. doc would prescribe "HRT" of 200 mg enanthat and 200 mg deca (unless yuo are an HIV/AIDS patient). THis sounds like one of those "life extention" or "anti-aging" type clinics and not something the vast majority of IM or endocrine docs would do. If they send a questionaire and a nurse out to do a physical, yuo've got yuor answer.
THe drugs will take about 5 half-lives to get below the active threshold, but normalization is a whole 'nother thing, and this is where it gets tricky. The reason yuo feel like an "old man" when yuo some off, is that there's no test or other AAS, estrogen levels are higher due to aromatization, AND cortisol levels that have been suppressed all this time are rebounding. So, strength and size are dropping, muscles are getting softer, fat is being added, and everything aches, while yuo get weaker and struggle with workouts yuo used to man-handle. This is why people go on after being off for only short periods of time.
Yuo could try some longer-term, rotating type PCT, but the only way to know how this is working is to get blood work done every couple of months. Ideally, this would be done working with an endocrinologist who's had expereince with athletes, AAS, and long cycles before. Based on what little info yuo've given here, I'd really encourage yuo to do this. Once yuo get normalized, if yuo are still hypogonadal (low testeosterone production), then yuo can see about real HRT (NOT the excessive doses that someone is calling HRT under the giuse of "anti-aging," unless yuo are HIV positive ir have AIDS). The good news is that HRT in the 100-150 mg range will actaully work pretty well IF yuor diet and training are strict!