You can visit there anytime. 99% there is no problem of accomodation. even in satsang days i have visited on the spot and i'v got accomodation there...
there is a major availability of acomodation u not need to worry at all just go there and go to sarai office, u'll get the accomodation.

Brother if you have not received any reply against accommodation letter then when you will reach beas, kindly go on Accommodation office located on Gate No.1 & tell him you send the letter for accommodation but u have note recvd any reply if your letter received by Dera accommodation incharge they will allot the room or sarai .