Do you have some way of quickening the spell ?(casting time 10 min). If so who do you send and what do say.
"We can delay it so that it is cast inside and then doesn't trigger until we walk outside."
Delay Spell feat.
"We could also make the sending less time to cast, one minute instead of ten."
Rapid Spell
"We could cast a contingency so the the sending goes off as soon as we step outside."