Temporary bracing of the wall logs could be done with vertical wales inside and out. I'm assuming that it is a chinkless coped design, so to tie inner and outer wales together without introducing holes in the logs, you'd have to take advantage of window openings, then to tie tops together going over top of top course, under the bottom course. 4x4s or 2x6s would probably be sufficient to maintain stability of the wall logs.
Not sure what you intend from here. You planning on jacking up the structure to perform foundation repairs?

Sent from my SM-G955U1 using Tapatalk