Not necessarily impossible, but do your homework. No Dynon system is IFR legal on it's own. At a minimum, you need a certified GPS. To really be an IFR plane, you'll want a nav/ils radio and indicator. This can easily be $7-$10k worth of equipment if you find used or remanufactured components. That's before you even get to a PFD, switches, fuses, autopilot, wires, adahrs, elt, intercom, etc. If you want something like a GNS430 in a Dynon panel, I don't think $20k is going to get you there. Forget about anything newer.
Like I say, not necessarily impossible, but it would be tough, and likely involve installing pretty dated equipment. Sure it would be nice to have the capability, but you won't keep your cost down if you install all the "nicetohaves". I'm not trying to talk you out of it, but if you are retired, don't enjoy IFR, and want to control costs, why not just wait for better weather and enjoy the Kitfox as god intended?