My mil is pissing me off again! And now my sil too!

My sister in law is getting married at the end of August in NY. My little guy will almost be 4 months old. We are flying in from Florida so during the wedding my aunt is watching him. The other day my husband gets a text from his sister telling him there are only 4 rooms left at the hotel under the block. Why in the world would we be staying at the hotel when my entire family lives in NY and we can stay with one of them. We are spending almost $1000 just to fly in, why would we pay to stay at a hotel? I know if we don't stay at the hotel she's gonna be all pissed off at us. Let me just mention that she and my in-laws did not stay at the hotel for our wedding and they were traveling from out of state.

So now my mil texts my husband to see if we are getting a room or we could stay with them. My husband responds and says it depends on the baby and my mil wants to know what depends on him. Gee idk the fact that I don't want to share a room with my in-laws and I don't want to leave my 4 month old son over night regardless of who he's with. I'm sure my aunt would do it in a heartbeat but I'm not ready to leave him. It pisses me off that she expects me to leave him overnight and just assumes my aunt would keep him overnight.