There are a lot of possible issues here:-
1. Is the landlord breaching the employment contract if he sells your home & you are evicted? This probably depends on the exact wording of the contract.
2. Are you an agricultural occupier, because different rules apply to them than to others?
3. If the home is sold will you be evicted or will you be offered a tenancy (presumably at market rent) by the new owner?
4. Will your employer increase your wages to compensate for loss of the low rent home? This again probably depends on the wording of the contract, and it may be something you could take to an employment tribunal as a complaint against the employer.
5. If you are evicted, will the Council have to house you? There are only certain categories of homeless people the Council has a duty to house.
6. Could you get help elsewhere with rent? Depending on your income and savings (if any) you might be entitled to housing benefit and council tax benefit.
You will need advice on these issues and a good place to start might be your local CAB, but I suggest that - as this is apparently so long into the future - that it might be better to leave it until nearer the time. If (as you imply) other employees will also be affected it would be best to act as a group if you can.