Sky Wave I cannot answer that question. But I think it unlikely that the LBA would be happy if it knew. Why don't you ask your management to find out? Tell them to ask for Referatsleiter Flugbetrieb 004953123550 in Braunschweig.
Summarising what others have posted, Westjet use 5000 pounds minimum divided by 2.2 is 2272 kg for the 737, just under one hour. 42south says they carry 60 minutes fuel in New Zealand. In Germany my company does not allow planning without an alternate and we are required to arrive with alternate plus final reserve unless the conditions I listed earlier are met, absolute minimum 1800kg.
Easy and possibly others seem to be planning with less, which is a significant competitive advantage if it is allowed.