It is possible to get some local assistance with cleaning and moving through a request on Point Interface or direct referrals. There aren't any "official" moving services here.
Moving companies from the mainland US often have problems fulfiling move contracts because crossing into Point Roberts through Canada requires that the driver and assistants have valid passports. Do not underestimate the importance of this! There is no ferry service and it is difficult to find transport options - you may need to drive the truck over yourself in smaller shuttles!