When I was weaning I had my son down to a night and evening nurse for a while so I think younshpuld be okay on that.
You won't be able to fully nurse on weekends, no. In fact you should probably wean down before you go back or you're going to be hurting a lot and potentially cause yourself some problems if you go cold turkey.
Can you really not pump? You are legally supposed to be able. If you would prefer not to (I don't fault anyone for not doing it, I hated pumping but fortunatelymy son was at an in building daycare so I could pop down to nurse), that fine, but if it's an employer won't let you but you would like to thing you might want to look into some legal resources. The ACA has provisions that protect the right to pump.
https://www.dol.gov/agencies/whd/nursing-mothers/faq