IBM has run this play before so do not expect to game the system. When my department did colocation in 2016 through 2019, you had 4 options:
(1) You had to be in the office at your new location Monday through Thursday. They did not require you to move but to just be onsite. So, theoretically you could commute every week if you had the desire and the funds to cover your costs.
(2) If commuting or moving was not feasible, you would separate from the company and be paid severance
(3) If you said you were going to move, you had 5 months to get to your new location. Once you moved, to get your relocation allowance , you provided documentation to IBM such your new as a lease or mortgage agreement. Then you received the relocation money.
(4) If you said you were going to move and did not report to your new location on the required day, it was considered an “abandonment” of your job and you were separated without severance.
The only exceptions were true hardship cases that went before a panel for review. An example of a hardship case was when 2 IBMers were married and one IBMer was required to relocate. The panel agreed to let the 2 married IBMets continue to cohabitate and not require the employee to move. But, IBM required the employee who got the exception to sign an agreement that if the marriage dissolved, they would report to their new work location in X number of days.