For just 6weeks maybe you are better served simply to just ask hotels you are interested if there is a corporate discount code offering 10-20% off that they are happy for you to use for a discount on a continuous 6week reservation.


Sucess (or not) for a discount rate contract always depends mainlyy on whether hotel will have empty rooms 7-nights a week for your 6weeks. If hotel is usually sold out 35/42 of your stay period, hotel does not need to discount your stay.
There needs to be a win for hotel, such as guaranteed nights income, on nights when hotel expects to not sell their rooms. No way are they going to discount a stay unless you sign contract guaranteeing to pay nn weeks, so do not expect a contract with discounted rate without a minimum period tie-in. You could probably contract to hotel minimum 6weeks stay, extendable by 1week periods.

1x room for only 6weeks is not going to be worth the hotels revenue managers time to negotiate a special 1-off price.
The 1-off 42nights income is just not substantial enough, especially if hotel is normally fully occupied on most of your stay nights.

Hotels do not need your 42nights business if say regularly full m/t/w/t nights for business at full rates
Maybe for hotel not full on any midweek nights, and with even lower occupancy percentage on non-business Fri/Sat/Sun nights , hotel might say yes as guarantees 18nights on poor occupancy weekends nights

Which ever chain and hotel, even if they offer you a discount it will be subject to you signing a contract to guarantee you will pay that whole 6weeks you mentioned, you can't leave early and not pay the contacted 42nights. Really a bit like booking one 6weeks bar non-cancel rate.