I'm flying tomorrow BOS-IAD-DAY, leaving at 7:25pm and getting into DAY at 11:23pm. I've been monitoring the BOS-IAD flight I'm on the last few weeks and it seems prone to delays of 30+ mins. The flight comes in from DEN and last nights delay was due to - "awaiting crew arrival in DEN". My connection is 47 mins, and after reading multiple horror stories regarding UA and their strict enforcement of T-15 rule, I'm concerned about making the flight.

So I'm prepared, if tomorrow's flight is also delayed due to something other than weather (like awaiting crew arrival) and I miss the connection to DAY, as its the last of the evening, am I stuck finding my own hotel? Also, as this is a quick 1 1/2 day trip to attend a birthday party for my 90yo grandmother, being rebooked the next day is severely going to restrict my trip. In short, it becomes a trip in vein at that point as I fly back Sunday morning, so will then be there less than 24 hours. Will UA just offer to rebook me back to BOS and refund my ticket?

Thanks in advance for all the help,

(Please refrain from the "if this trip was so important, why didn't you book an earlier flight, etc." Not everyone has the kind of job where we can request off anytime we want. I work in sales, it's the last day of the month, and I have to be in the office. The 7:25 flight is my only option.)