As with most of the others, I'd be very hesitant, for a number of reasons. I wouldn't want my child away for 3 nights for "no reason" beyond potty training. If she was watching kiddo and you guys were going on a long weekend, that would be different, but it doesn't sound like that's the plan. AAP (American Academy of Pediatrics) notes that it can take a child months to *years* after day-time training to be night-time trained. Believe me, I understand the drive to get kids out of diapers--each weekend, we have 2 in pull-ups, and 1 in diapers, and still wake up to a soaked bed (thankful for mattress pads). But, there's not a reason to rush it, and, developmentally, it is not common for boys (or girls!) to be reliably night-trained at 2.5yo. I also wouldn't want to make it a potential control issue, or a time when the child is sad that he couldn't remain dry as hoped for.
--Mimi
Mom to Lala (2004), Bonus Mom to Big Sis 1 (1991) and Big Sis 2 (1992)
Grammy to Big Kindy Kid (2011), Big Pre-K Kid (2012),
Grandbaby Appendage (2014), and New Baby Grandboy (summer 2017)