I have a 10+ yr old philodendron with several, 20+ ft shoots. It is in a large pot, but I believe it is root bound. My question is, when I re-pot it, can I split the plant? It’s so giant, the next sized pot would be too large. Any insight would be greatly appreciated!
Houseplants called "philodendron" are a diverse group and we don't know what kind you have but the following describes how to grow them.
Based on your description, we suppose your philodendron is a vining kind with trailing stems that may be tangled and intertwined. Splitting the plant might be impractical if the stems are tangled. If so, stem and root pruning may be the best way to keep the plant in bounds and allow for re-potting.
Otherwise, consider propagating it by starting cuttings that can be grown until you are ready to replace the original. Learn more about that here:
The following general information about repotting may be useful.