Is it permissible to perform ghusl from janabah by wiping the body with the hand without pouring water, due to the lack of sufficient water, while it is possible to perform wudu later in the work restrooms? And is it permissible to perform tayammum in this situation given the unavailability of earth or sand and the lack of knowledge of the correct method due to the differences among the madhhabs?

It is not sufficient in Wudu and Ghusl to merely wipe the limbs with water. Rather, it is obligatory to pour water and ensure its flow to cover all the limbs. The flow of water in Ghusl is sufficient without rubbing, provided there is a strong presumption of thoroughness (isbagh). If the household members do not permit bathing with their water, then you must search for and purchase water. Do not resort to Tayammum except when unable to perform Ghusl from Janabah.