Something to keep in mind about ice: small pieces of it, or thin sheets of it, are very brittle. Large, thick pieces of it, however, are quite strong. Ice at freezing temperature has the hardness of lead, and around -70 C, it is as hard as titanium. This is good news for you, as most cryogenic options can lower object temperatures as far as -80 C
I'm operating under the assumption that the frozen human in question will contain no empty pockets of gas and be up to 75% solid, frozen H2O.
Bearing that in mind, the human body is more flexible and inherently resistant to damage because of that. Much like a flexing bridge, the human body can absorb and distribute force rather than deflect it completely. So I looked into the breaking strength of solid Ice.
This study contains a helpful graphic on page 3 of the various breaking strengths of ice found in various parts of the world. This ice naturally forms with a lot of impurities. I feel this is a fair comparison, as humans that are cryogenically frozen are mostly made of water but contain up to 25% other compounds.
The table gives quartile strengths from 200 to 800 lb/in^2. A good median across all sites on the table is 500 lb/in^2, or 87500 pascals.
In order to compare this to the human examples you give above, I converted the max Gs experienced to pascals as well. In order to do this, I used an average human surface area of 1.7 m^2. After that, I took your initial max Gs multiplied by the average human mass to get our force applied (G Force = Gs *(9.81 * 70)).
Lastly, using the assumption that the forward-facing body of a human is roughly 1/3rd the total surface area, I solved the following for a given human form undergoing the G force you listed:
Max Pressure = G Force / Area
Max pressure (forward/backward) = 4*686.7 / 0.51 = 5385.9 pa
To solve for a feet-first acceleration:
Max pressure (up/down) = 4*686.7 / 0.272 = 10098.52 pa
Here we see that the max pressure of a thawed human is much less than that of ice. A fully-frozen human will benefit greatly from that added structural integrity, and be more than capable of surviving much greater forces. Using this breaking strength for Ice, up to 8 times the acceleration, or as much as 32 Gs (313.92 m/s^2).