Among the clipless systems, the absolute, easiest to get out of is Shimano's mountain bike SPD system, assuming the following:
1) You need to back off the release tension (very easy with an allen key), almost all the way out.
2) You make sure to get the optional Shimano multi-release cleat (standard with a few of their pedals, but optional on most). This cleat allows much easier release because it doesn't have to be an exact angle of movement.
The unclipping motion is heel out. Toes stay the same, but heel swings out.
If that doesn't work, your best bet may be a very large platform or touring pedal fitted with what we call a half clip. This is a plastic or metal toe clip that doesn't have anything to put a strap through. It keeps your foot from moving forward off the pedal, but it doesn't restrict any other movement of the foot off the pedal.
You may have to experiment a bit to see what works best. If it was me, I think I would feel safer using the half clips rather than clipless pedals in a case like yours. It's just that clipless pedals can sometimes get finicky about both clipping in and clipping out. Cleats wear out, there is cleat positioning to worry about, and it's like any other mechanical system. The half clip, on the other hand, is just a regular pedal with a plastic tip bolted onto the front that keeps the foot from slipping off.