OEM spark-gap ignition is actually extremely reliable. Two stories-
Last fall I went to a camping event with a 1942 truck. 6V, electric start. Overnight, temps went down to 24°. In the morning, there was frost on the outside and inside of the windshield, and even on the fabric seats. Set choke and throttle, switch on, press starter, fired on the first spin.
One night on the highway my 66 died on the freeway just outside Miami. No tools, so I used roadside debris to pop the clips on the distributor. It's a dual point, and one of the cam followers had snapped off. Back to debris, found a small piece perfect to pinch into the broken points, drove home. Try that with dead electronics.