If you have space to store them, another good solution is to buy USED solar panels for 50-80% less than the cost of new panels. Then, buy some wiring, a fuse, and a solar controller and you have a very inexpensive portable solar setup. If it ends up growing legs and walking off (stolen), you won't be out much (especially if you can keep your charge controller somewhere safe/secure).
I have purchased 250w working panels for as low as $35 each. Check your local craigslist, facebook marketplace, etc. Test the panels before you buy, but there are no moving parts and they should last a long time (20yrs+).
And to answer your question, yes, you should be able to hook up separately from your existing solar.
Good luck!
Chris