scottyk,
I can so appreciate your situation and desire to find even a little of the yellow meal. In addition to honing you skills panning in the garage there is something very useful you can do with a little of your time and that is researching where you Can go in the Black Hills of SD. In addition to this research you can exercise your body. Are you comfortable while you are panning in the garage and I mean your body? Out in gold country you might not be able to make yourself so comfortable as you can in your garage at home so prepare for it with simple exercises: crunches, push ups, stretching, lifting 5 pound weights or less or more depending on the condition you are in.
In the summer is when I usually get out as in the winter the river is dangerously high, fast and cold. In the summer like mid July the water temp is 54 F and that is not exactly warm but with the air temp around 100 it makes the water feel good so I pan while sitting in the water. This way I can sit on a piece of blue foam pad and lean against a boulder to support my back. This is primitive however, anything one can do to keep their muscles happy needs to be done. I can not stress the exercise enough and I do not care how young or old a person is, do the exercises! For instance I will be 67 years of age in late April 2011, I expect to carry 85 pound packs this summer(my packs weighed that much last year), I expect to be cutting trail , I expect to be moving boulders I AM very physically active when I'm out in the mountains as that is what is required to do this AND be able to come back out under your own steam. So, to keep up with my life style I exercise every morning: 1000 crunches, 300 left/right side crunches, 3 100 counts laying on my stomach with chest and legs raised off the floor, all kinds of stretches, I use two 5 pound weights during some of the stretches and then I do a series of just weight lifts and all of that takes about 75 minutes. Do I enjoy exercising, no. Do I need to exercise, yes. Will the exercising help me this year, yes.
Just because I exercise does not mean I will not have some form of trouble out there but in 2008 on my way in with an 85 lb pack I managed to severely sprain my left ankle and break one of the long vertical bones in the calf area of the same leg. I was hiking alone. For a fleating part of a second I tried to convince myself I was ok and could just keep hiking in, then reality checked in and I chose to prepare to hike out. The hike out part required some medication so I pulled out the first aid kit and took two Tylenol with Codeine pills (left over from my second knee operation on the left leg). A half hour after taking the pills the pain was easing. I reshouldered the pack without too much damage to my right shoulder and slowly hiked out to my truck. So being prepared with some muscle power as well as simple first aid supplies is always a good idea!
Understand the area you are going to go too. What typical weather for the time of year you will be going, what are the roads like, what type of bugs and reptiles are there, is it safe or even possible to start a fire for cooking and what emergency supplies should you have with you! Now it is possible to find gold in a stream right next to a KOA campground or to find it in a river you can drive your vehicle right up to.
So, there is plenty for you to do while the ground is frozen solid. Stick with the simple equipment for now like your gold pan kit and some simple digging tools. Gerber has a "tiny" collapsable/folding shovel, scaled down from the current issue GI entrenching/latrine tool, and it is really strong and useful, about $30 unless you can find it on sale. Its what I carry along with my Batpan, tuna fish can classifier, scraper, Keene A-52 sluice box (I'd go with a McKirk brand for my first choice now) and a few odds and ends that add up to between 15-20 lbs. Have fun, stay fit and make the trip very enjoyable for the wife so she will want to go again! 63bkpkr (aka: 'lefty')
note: 3xflyfishers comments are something else you could do while the ground is frozen.
also, pictures of classifiers/sifters homemade, purchased from Bed Bath & Beyond store, the one that came with my Batpan
Gold is extremely hard to find in your area and prospecting is hard enough without the odds being stacked against ya. NEVER SPEND ALL YOUR TIME DOING ANYTHING--gets old and tiring pretty quick--John
Got some stuff on order to start the building of my home made sluice!! Probably going to hook up a electric pump and so some testing in the garage and see if I can catch some lead and rare iowa gold with it 
I have a couple myself, Fox Body street/strip car and a 03 Cobra 
